International One Health Symposium 2025

Oct 13, 2025, 12:00 PM → Oct 15, 2025, 4:00 PM Europe/Berlin

https://www.hotel-berlin.de/en (Hotel Berlin, Berlin)

 

Welcome to the International One Health Symposium 2025

 

Date: October 13th - October 15th, 2025

Venue: Hotel Berlin, Berlin, Lützowplatz 17, 10785 Berlin

 

Participation fees:

€ 95 for undergraduate student, graduate student, PhD student

€ 290 for postdocs, senior scientists, public health workers, etc.

 

Certification

The conference has been certified with 13 ATF hours by the "Akademie für tierärztliche Fortbildung".

An application for continuing education recognition for physicians has also been submitted to the "Ärztekammer Berlin", and we are currently awaiting certification

 

The abstract submission deadline has been extended to June 15th, 2025.

Please submit your contribution on one of the following topics and read the instructions carefully:

• AMR

• Agriculture & Health

• AI in Health Research

• Climate Change & Health

• Conservation & Wildlife Health

• Emerging Pathogens

• Environmental Pollution & Health

• Genomics & Proteomics

• Novel Methods

• One Health in Public Health

• Pandemic Prepardness & Prevention

• Social Sciences & Health

• Vaccines & Immunology

• Vectors

 

Review results

August 20th + September 2nd: All results have been sent out.

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Note: Foreign participants from all countries (except Germany) who submit an abstract by June 15th, 2025 will have the opportunity to apply for one of five travel grants to cover their travel expenses.

We will automatically contact all eligible applicants by e-mail in the week from June 16th to 20th, 2025 and explain the next steps. If you have any questions about the travel grants, please contact: Anett Wagemann, info@onehealthplatform.net

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Conference language: English                                                                 

Please keep an eye on your e-mail for further announcements.

 

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Funded by:

                 

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Mon, October 13

12:00 PM → 1:00 PM Registration & Finger food

1:00 PM → 1:20 PM Welcome Note

Conveners: Stephan Ludwig, Rita Schwarzelühr-Sutter (BMUKN)

1:00 PM Welcome Note: One Health Platform

Ladies and Gentlemen,
We are delighted to welcome you to the second International One Health Symposium in Berlin under the overarching topic “Challenges in a rapidly changing environment”.

Following the further development of the German Research Platform for Zoonoses, which was founded in 2009, into the One Health Platform (OHP), we are delighted that the path to establishing an interdisciplinary One Health research community has been a successful one. After almost two years of funding, the OHP has around 1700 members from various disciplines such as veterinary medicine, human medicine, biology, environmental as well as social sciences. The first pilot and inter- and/or transdisciplinary networking projects have now been launched and the enormous number of applications submitted shows us both your wealth of ideas for exciting One Health topics and the urgent need for research in this area.

In particular, networking with the environmental sector is a central concern of OHP in order to be able to address the topic of One Health in its entirety. This applies not only to the outlook for national research cooperation. Strengthening international networking in particular is a major task that OHP will continue to focus on in the coming years. This networking begins not only with the initiation of contacts between established scientists, but above all in the area of young scienstists, the strengthening of which is also one of the major priorities on the OHP's agenda.

This year's conference will showcase the lively discourse between the various One Health disciplines in an exciting program.

We wish you many interesting discussions over the next few days and look forward to an exciting meeting with you all.

On behalf of the Office of the One Health Platform

Prof. Dr. Stephan Ludwig, Prof. Dr. Martin H. Groschup, Prof. Dr. Fabian Leendertz

Speaker: Stephan Ludwig (One Health Platform Münster)

1:05 PM Welcome Note: Federal Ministries

Dear Ladies and Gentleman,

I am delighted to speak to you today on behalf of the Federal Environment Ministry and the five other federal ministries involved in the One Health research agreement.

Two years ago, the well-regarded German Research Platform for Zoonoses became the One Health Platform, broadening its focus beyond human and animal health to include environmental health. This was the right decision. The Platform involves six federal ministries – Health, Agriculture, Research and Technology, Economic Cooperation, Environment and Defence. I would like to thank the staff of the Zoonoses Platform office and the members of the Scientific Advisory Board, who have been instrumental in facilitating the transition to the new platform. Their experience and expertise lay the groundwork for managing and improving the new platform. Your work on the One Health Platform is invaluable. The Platform’s research agenda shows that you are already putting the principles of the One Health approach into practice.

At a time when we are facing global challenges such as pandemics, pollution, climate change and biodiversity loss, it is essential that we take an integrated view of human, animal and environmental health. And underscore the importance of One Health as an integral part of our political and scientific agenda. One good example of how human and animal health and the environment are closely interconnected is climate change: its far-reaching impacts are already being felt today but will become even more serious in future. Higher temperatures are negatively affecting human and animal health, and diseases once rarely seen at our latitudes are now spreading. And the impacts of climate change on the environment affect humans and animals, too – for example water scarcity – a problem compounded by increased pollution.

As a result of insights like this, the One Health approach has gained in importance in recent years, making its way into policies at national, European and international level. I would like to outline this briefly.

At international level is the WHO Pandemic Agreement, which was concluded after lengthy and difficult negotiations. Article 5 explicitly references One Health, attesting to the importance of this approach. One Health is also firmly established in international environmental protection and climate action. For example, One Health has been included on the agenda of the next major climate conference this year, COP30, and in the WHO Global Action Plan on Climate Change and Health.
The G7 and G20 countries have also recognised the importance of the One Health approach in relation to human health, agriculture and the environment. In their most recent communiqués, the G7 and G20 emphasised the need to strengthen health systems around the world, in line with the One Health approach. We know from experience how important this is, because pandemics and pollution know no borders and require a coordinated international response.
Finally, the Danish EU Council Presidency has also included One Health on its agenda. A high-level stakeholder conference on the One Health strategy is planned with the European Commission for December. It will promote an integrated view of health, veterinary and environmental aspects with the aim of increasing resilience.

At European level, the German government participates in various European partnerships that put the One Health approach at the centre of their research activities. Three partnerships have recently been launched or are about to begin: the European Partnership on One Health Antimicrobial Resistance, the BE READY NOW partnership for pandemic preparedness and the Partnership on Animal Health and Welfare. The first two aim to further strengthen interdisciplinary and transdisciplinary cooperation through European research projects over the next seven years.

The German government also supports the IAEA’s Rays of Hope initiative, which targets healthcare systems for radiation medicine in low- and middle-income countries. This transfer of expertise and technology will make modern radiotherapy applications available to treat cancer, for example, in line with the overarching goals of One Health.

In Germany, the One Health approach is now also established in policymaking and research. Some ministries have set up divisions to focus on One Health, giving rise to various strategies, including one by the Federal Agriculture Ministry. One Health is also being addressed in subordinate authorities, such as the German Environment Agency, called UBA for short, which is part of my ministry. UBA has initiated a ministry-wide discussion process on how the approach can be integrated more fully into its own activities. It is currently setting up a strategic project group to advance this principle.

UBA firmly believes that the One Health approach can make an important contribution to achieving national and international sustainability goals and bringing about a green and socially just transition. Fundamental principles include the importance of respecting planetary boundaries and environmental justice.

And there is well-established dialogue between the ministries. All ministries are kept informed about ongoing activities, can coordinate their efforts, work together on issues and forge international contacts – most recently with the WHO, for example. One Health is also a component of various German government strategies, such as the German Sustainable Development Strategy, the National Biodiversity Strategy and the German Antimicrobial Resistance Strategy. Even though One Health is not explicitly mentioned in the German government’s coalition agreement, it contains many indirect references to it.

What does this have to do with you, with science and research? The answer is: a lot. As members of the One Health Platform you are leading by example and already driving inter- and transdisciplinary research. Without research and science, our policymaking is on shaky ground. Science provides the basis for drawing up informed and effective policies. Research institutions and universities play a crucial role in developing innovative solutions and providing data that is essential for policymaking. It is particularly important for disciplines to be interlinked and funding to be targeted accordingly: starting this autumn, the Federal Ministry of Research, Technology and Space is planning to fund seven interdisciplinary and transdisciplinary research networks on pandemic prevention and response with a One Health approach. The research networks focus on different subjects including influenza, tick-borne diseases, West Nile virus and antimicrobial resistance. The plan is for these seven networks to collaborate with the One Health Platform. For each network the coordinator will present their work programme at next year’s One Health Symposium. International partnerships, such as those promoted by Horizon Europe and other research programmes, are also very important.

Without sound scientific knowledge, we policymakers are groping in the dark. We would be unable to identify new health risks in time, nor would we know how to respond effectively. Only with well-networked research at national and international level, which takes all One Health sectors equally into account, can we find the right answers.

Let us – the researchers and policymakers – continue to work together to reinforce the importance of One Health in our political and scientific discourse and to step up national, European and international cooperation. This will ensure that we can protect the health of people, animals and our environment.

In this spirit, I wish you a stimulating and productive conference!

Rita Schwarzelühr-Sutter
Parliamentary State Secretary
Federal Ministry for the Environment, Climate Action, Nature Conservation and Nuclear Safety (BMUKN)

Speakers: BMUKN (Federal Ministry for the Environment, Climate Action, Nature Conservation and Nuclear Safety), BMLEH (Federal Minister of Agriculture, Food and Regional Identity), BMZ (Federal Ministry for Economic Cooperation and Development), BMVg (Federal Ministry of Defence), BMG (Federal Ministry of Health), BMFTR (Federal Ministry of Research, Technology and Space)

1:20 PM → 1:50 PM Keynote I: Wim van der Poel: One Health Approach to Control Zoonoses in Changing Animal Production Systems

Convener: Stephan Ludwig

2:00 PM → 3:45 PM Session 1: AMR

Conveners: Roswitha Merle, Birgit Walther

2:00 PM Phenotypic resistant single-cell characteristics under recurring ampicillin antibiotic exposure in Escherichia coli

Non-heritable phenotypic drug resistance toward antibiotics challenges antibiotic therapies, and phenotypic resistance fosters the evolution of heritable resistance. Here, we describe single-cell characteristics of phenotypic resistant E. coli cells and compare those to characteristics of susceptible cells by exposure to different levels of recurrent ampicillin antibiotic. Contrasting expectations, we did not find commonly described growth arrest of cells. We find that under ampicillin exposure, phenotypic resistant cells reduced their growth rate by about 50% compared to growth rates prior to antibiotic exposure. The growth reduction is a delayed alteration to antibiotic exposure, suggesting an induced response and not a predetermined state as frequently described. Phenotypic resistant cells exhibiting constant slowed growth survived best under ampicillin exposure and, contrary to expectations, not only fast-growing cells suffered high mortality triggered by ampicillin but also growth-arrested cells. Our findings support diverse modes of phenotypic resistance, and we revealed resistant cell characteristics that have been associated with enhanced genetically fixed resistance evolution, which supports claims of an underappreciated role of phenotypic resistant cells toward genetic resistance evolution. A better understanding of phenotypic resistance will benefit combatting genetic resistance by developing and engulfing effective anti-phenotypic resistance strategies.

Speaker: Ulrich Steiner (Freie Universität Berlin, Institute of Biology, Berling, Germany)

2:15 PM The accumulation of antimicrobial resistance genes in a wild chimpanzee population over seventeen years.

The selective pressure exerted by the massive use of antibiotics has led to a rise in antimicrobial resistance (AMR), posing a serious global health problem. This issue is particularly concerning in many regions of Sub-Saharan Africa, where easy access to antibiotics without a prescription and frequent self-medication foster the emergence and spread of antibiotic resistance genes (ARGs). This environment is conducive to the selection and transmission of resistant bacteria, which can affect not only human health but also that of animals and surrounding ecosystems. However, understanding the actual impact of human activity on the spread of resistance genes requires overcoming a major challenge: the difficulty of distinguishing natural from acquired resistance. Here, we use a longitudinal approach to test whether the observed increase in AMR among humans and livestock in West Africa was accompanied by a flow of ARGs into wild chimpanzees (Pan troglodytes verus), our closest genetic relatives, in Taï National Park (TNP), Côte d’Ivoire,the largest remaining fragment of primary forest in West Africa. We analyzed 410 fecal samples from three groups (NEast = 9; NNorth = 15; NSouth = 17 years), collected over a 17-year period, using hybridization capture and high-throughput sequencing to screen for more than 2,000 ARGs to assess ARG richness and resistance type diversity. Both the abundance of ARGs and the diversity of antimicrobial resistance classes increased; we detected ARGs conferring resistance to drugs of high clinical importance (fluoroquinolones, peptides, aminoglycosides, beta-lactams, glycopeptides, glycylcyclines, macrolides, rifamycins, streptogramins, tetracyclines) and moderate importance (diaminopyrimidines, sulfonamides, lincosamides, phenicols, phosphonic acids, sulfonamides), providing strong evidence for ARG flow into this isolated population.

Speaker: Mr Coch Tanguy Floyde Tanga (Helmholtz-Zentrum für Infektionsforschung (HIOH))

2:30 PM Environmental characteristics associated with the resistome from wildlife populations of house mice

Antimicrobial resistance poses a significant challenge to global health. However, the factors that maintain antimicrobial resistance genes (ARGs) within wildlife microbiomes, particularly in species inhabiting human-dominated landscapes, remain unclear. In this study, we analysed ARGs in 846 faecal samples collected from house mice (Mus musculus) on farms in Germany between 2016 and 2022 using metagenomic sequencing. We fitted joint species distribution models to determine which characteristics of the mouse, landscape or climate explain the presence of ARGs within the house mouse microbiome. A model incorporating all identified ARGs revealed that environmental variables and livestock accounted for over 25% of ARG variance, whereas climatic and mouse-associated characteristics accounted for less than 4% each. When differences in genomic localisation, mobility potential and drug class between ARGs are included in the model, agricultural land use and exposure to livestock interacted with genomic mobility potential. In particular, pig density was strongly associated with integron-encoded genes conferring resistance to aminoglycosides and trimethoprim. Our data suggest that landscape conditions influence the presence of specific ARGs with mobility potential within the microbiomes of house mice. A better understanding of the factors impacting ARG prevalence in wildlife species is crucial for determining transmission of antimicrobial-resistant microorganisms from animal reservoirs.

Speaker: Víctor Hugo Jarquín-Díaz (Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany)

2:45 PM Occurrence and characteristics of methicillin-resistant Staphylococcus argenteus in food products in Germany

Staphylococcal species are well-known zoonotic opportunistic pathogens leading to clinical symptoms that range from skin and soft tissue infections to severe blood stream infections as well as human food poisoning. In 2015, S. argenteus was defined as a separate species within the S. aureus complex but with a similar pathogenicity in humans, proven by occasional infectious disease and foodborne poisoning outbreaks especially in Asia and Australia.
To identify methicillin-resistant S. argenteus in the German food chain, we analysed ~6000 presumptive methicillin-resistant S. aureus (MRSA) isolates that have been provided to the German NRL-Staph between 2014 and 2024, mostly in frame of the national zoonoses monitoring. In total, we identified and further characterised 12 mecA-positive S. argenteus strains by whole genome sequencing and phenotypic antimicrobial resistance (AMR) testing. Because all identified S. argenteus isolates originated from Asian seafood, a small study on fish and seafood imports to Germany followed in 2024/2025 which resulted in further ten isolates. All isolates showed a highly clonal structure and less AMR than MRSA from seafood, but harbored relevant virulence genes like staphylococcal enterotoxin and immune evasion cluster genes.
In conclusion, AMR and potentially virulent S. argenteus strains are regularly present in fish and seafood from Asian regions, but have not yet been observed in German food products. The strains might represent a threat to human health.

Speaker: Sven Maurischat

3:00 PM Food System Changes in One Health: Options for Reducing Antimicrobial Use

Background: Inappropriate use of antimicrobials has been linked to resistance to antibiotics in both humans and animals. About three quarters of total antimicrobial use (AMU) originates in agriculture, but a comprehensive understanding of options for reducing agricultural AMU is lacking. Here we estimate the effectiveness of mitigation options across the food system at global, regional, and national levels, including improvements in biosecurity, reductions in food loss and waste, and dietary changes towards healthier and more sustainable diets.

Methods: For our analysis, we first estimate agricultural AMU attributable to both livestock production and seafood production from aquaculture. To estimate AMU per product, we used region and commodity-specific AMU application rates and paired them with animal numbers corrected for their weight at treatment. We used a global food-system model with country-level detail to estimate the impacts of changes in food loss and waste, dietary changes to a set of healthy and sustainable diets (flexitarian, pescatarian, vegetarian, and vegan), and improvements in biosecurity measures on food production in 2030. We then paired the changes in food production across the different options and between 2020 and 2030 with the estimates of AMU per product.

Findings: We estimated agricultural AMU to be 102 kt in 2020, increasing by 18% to 120 kt in 2030, driven by population growth and dietary changes in middle-income countries. Improvements in biosecurity reduced AMU by 22% compared to no intervention in 2030, with greatest improvements in regions with high pork production such as Europe. Halving food loss and waste reduced AMU by 7%, with greatest reductions in regions with aquacultural production such as East Asia. Dietary changes to flexitarian or pescatarian diets reduced AMU by 42-44%, whereas adoption of vegetarian or vegan diets led to reductions of 88-99%, with greatest reductions in regions with high intake of animal source foods such as North America. Combining all measures increased the individual mitigation potentials (e.g., to 57% for combinations with flexitarian diets).

Interpretation: Achieving meaningful reductions in agricultural AMU will benefit most from a combination of measures, including improvements in biosecurity, reductions in food loss and waste, and dietary changes towards healthier and more sustainable diets with lower amounts of animal source foods. Dietary changes are not often considered One Health interventions, but their substantial mitigation potential warrants to be taken into account for effectively addressing the rapid emergence of antimicrobial resistant organisms.

Funding: Bundesministerium für Bildung und Forschung; Wellcome Trust

Speaker: Thomas Burke (University of Göttingen)

3:15 PM Landscape fragmentation and rural land-use drive antimicrobial resistance gene diversity in a wild primate

Antimicrobial resistance is a global health concern caused by the overuse of antimicrobials and environmental contamination. Wildlife exposed to disturbed environments can acquire resistant microorganisms, indicating environmental ARG (antimicrobial resistance genes) contamination and serving as ARG reservoirs. Here, we used a landscape-scale approach to test whether metrics of anthropogenic disturbance influence the abundance and diversity of ARG in brown howler monkeys (Alouatta guariba). We collected 377 fecal samples from 20 groups of howler monkeys. We extracted total DNA from pooled samples and performed shotgun metagenomic sequencing. We used the SqueezeMeta pipeline for metagenomic assembly and ARG identification based on the CARD database. We extracted landscape metrics representing habitat loss and fragmentation using ArcGIS. We applied generalized linear models to test the influence of landscape disturbance on ARG metrics. We identified 441 ARGs, mainly associated with aminoglycoside, carbapenem, and cephalosporin resistance. ARG richness increased with higher agricultural cover, habitat fragmentation, and water bodies in the landscape. ARG diversity and evenness were positively associated with pasture cover and water bodies. Landscapes with rural interfaces and higher fragmentation tend to increase the richness and diversity of ARGs in howler monkeys. Water bodies and pasture cover likely act as important environmental pathways for ARG dissemination.

Speaker: Vinícius Klain (Federal University of Rio Grande do Sul)

3:30 PM Anti-SARS-CoV-2 potential of RSK Inhibitors – Combining synergistic effectiveness and resistance prevention

SARS-CoV-2 infections can have severe consequences, especially for elderly and immunosuppressed individuals. Identifying novel antiviral treatment strategies is an important task, especially in preventing the selection of resistant virus variants. Such treatment strategies include host targeting antivirals (HTAs) and direct acting antivirals (DAAs), each with distinct benefits. Here, we show that SARS-CoV-2 is susceptible to inhibition of the 90kDa ribosomal S6 (RSK) kinases. RSK inhibitors (BI-D1870, BRD 7389) were tested as monotherapies and in combination with the DAAs Remdesivir (RDV) and Nirmatrelvir (NTV). Both RSK inhibitors exhibited anti-SARS-CoV-2 properties in a stand-alone treatment, as well as synergistic effects with the DAAs. Serial passage of B.1.617.2 under increasing inhibitor concentrations (BI-D1870, BRD 7389, RDV, NTV) led to the selection of DAA drug-resistant variants, while the virus remained fully susceptible to RSK inhibitors. Moreover, synergistic combination therapy (BRD+NTV) likewise did not select for resistant viruses. Testing DAA resistant viruses against RSK-inhibitor + DAA drug combinations still revealed a synergistic mode of action, whereas the RDV + NTV combination therapy showed antagonistic effects. In summary, we identified RSK kinases as so far unknown SARS-CoV-2 proviral factor and could show that combining HTAs and DAAs can be a promising new antiviral approach to increase the antiviral efficacy and mitigate resistance selection.

Speaker: Dr André Schreiber (University of Muenster)

2:00 PM → 3:45 PM Session 2: Emerging Pathogens I

Conveners: Corinna Pietsch, Sven Poppert

2:00 PM Epidemiology of Autochthonous West Nil Virus Infections in Lower Saxony in 2024

West Nile virus (WNV) is a mosquito-borne arbovirus causing West Nile fever (WNF) or neuroinvasive disease (WNND). WNV infections are notifiable according to the infection protection law. From May through November 30 there is mandatory screening of blood donors (BDs) for WNV in Germany.
In 2024 eight cases (5 BDs, 2 WNV, 1 WNND) of suspected WNV cases were reported to the local Public Health authorities; Thereof three cases were confirmed as autochthonous. Two of the reported WNV cases had been abroad. One BD was not confirmed. Two BDs were confirmed with Usutuvirus whereas two were confirmed with WNV clade II. Both WNV-positive BDs, from two different counties did not recall any symptoms prior to blood donation nor did they report any travel history outside Lower Saxony (LS) for the time period of 21 days prior to blood donation. After confirmation of the first WNV-positive BD in early September the public was informed by press release. Investigation of the WNND case revealed that the person contracted the infection in Lower Saxony. All three autochthonous WNV cases lived in or in the vicinity of counties where WNV-infections had been diagnosed among horses and birds prior or at the time of infection in 2024.
The occurrence of WNV cases in LS indicates that WNV circulates in Culex spp. populations in Lower Saxony. Awareness needs to be raised among the public towards preventive measures e.g. prevention of mosquito bites as well as eliminating breeding sites for mosquitos.

Speaker: Dr Christiane M Klier (Public Health Authority of Lower Saxony)

2:15 PM Viral Interference During Flavivirus Coinfections

Superinfection exclusion describes the phenomenon of closely related viruses being unable to simultaneously coinfect the same cells. Despite being reported across a wide range of virus families, no general mechanism responsible has been identified. To study how closely related viruses interact, it’s often necessary to use tagged or otherwise genetically modified viruses, since classic detection methods like antibodies or RNA/DNA probes are usually not specific enough to differentiate between them. This, however, comes with potential caveats: depending on the virus used, tagging it can lead to reduced replication rates, which could influence viral interactions. Additionally, any genetic modifications to a virus’s genome, even if not influencing its replication rate, could influence its interaction with the host or other viruses.
In this study, we describe an antibody-based staining method capable of differentiating the two closely related mosquito-borne Orthoflaviviruses WNV and USUV without any genetic modifications. We use it to characterize their interference with one another during simultaneous and sequential coinfections, finding evidence for superinfection exclusion occurring between them. We supplement our findings with qRT-PCR showing that reduced viral infection rates translate to reduced genome replication.

Speaker: Nils Tadewaldt (Friedrich-Loeffler-Institut)

2:30 PM Characterization of viral factors responsible for Arenavirus-host barriers in M. natalensis

Lassa virus (LASV) outbreaks cause up to 18,000 annual deaths in West Africa. Transmission mainly occurs through contact with infected rodents, with Mastomys natalensis as the primary reservoir host. Prior studies showed that homologous LASV strains (isolated from M. natalensis) cause persistent infections in Mastomys, while heterologous strains (isolated from other rodent species) are cleared rapidly. To identify viral factors driving these host restrictions, we created LASV chimeras by inserting single protein sequences from a heterologous strain into a homologous backbone.

The growth kinetics of chimeric and wild-type viruses were compared in vitro. Furthermore, one-week old Mastomys were inoculated with the different chimeras and monitored for four weeks. Virus titers in organs, as well as viral RNA levels and antibody presence in blood were analyzed.

All four chimeric viruses showed attenuated growth in vitro on Vero and Mastomys-derived cells. The homologous wild-type control caused strong systemic infections in vivo. The chimera with a heterologous Z protein showed a similar infection phenotype, however, it also caused pathogenicity. In contrast, the chimeras with the heterologous GP, NP, or L protein only led to low virus titers and rapid clearance, like the heterologous wild-type virus.

Our findings indicate that the LASV GP, NP, and L protein play important roles in the observed virus-host barriers, while the Z protein has minimal effect on host restrictions.

Speaker: Dr Chris Hoffmann (Bernhard Nocht Institute for Tropical Medicine, Virology Department, Hamburg, Germany)

2:45 PM A novel astrovirus isolated from a greater white-toothed shrew

Astroviruses are one of the major causative agents of non-bacterial gastroenteritis in children under the age of five. The number of astroviruses detected in different host species is increasing, but virus isolation remains rare, which limits subsequent investigations. In the present study, a novel astrovirus was isolated from a greater white-toothed shrew (Crocidura russula, family Soricidae), tentatively named CrussAstV.
Whole genome sequences of the virus isolate and of a C. russula were determined, and a close phylogenetic relationship to Jingmen shrew astrovirus 1, detected in Shantung white-toothed shrews, was demonstrated. Electron microscopy investigations confirmed the presence of virions with a star shaped morphology. The highest CrussAstV-RNA loads were detected in kidney tissue, which may indicate a potential transmission route via urine. Ongoing environmental and non invasive urine sampling of the C. russula colony, from which the original animal came from, has so far yielded negative results through RT-qPCR testing. Kidney samples from 24% of screened C. russula (n=243) carried CrussAstV-RNA, but none of 39 lesser white toothed shrews or 93 bicolored white-toothed shrews, even when trapped at the site of a positive C. russula.
In a One Health approach, future studies should evaluate the influence of anthropogenic land use and climate change on the range of these reservoir species to further assess the risk of spill over infections to other host species.

Speaker: Viola Haring

3:15 PM Middle East Respiratory Syndrome Coronavirus, an Emerging Zoonosis: 2022 Surveillance in One-Humped Camels in Nigeria

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a significant zoonotic virus that the World Health Organization (WHO) has classified as a priority pathogen due to its potential to cause epidemics. As of April 2025, an estimated 2,627 lab-confirmed cases of MERS-CoV, with at least 946 deaths across 27 countries, have been reported. Given Nigeria's porous borders and the transboundary movement of animals, the country is at risk for the transmission of zoonotic diseases, including MERS-CoV. From May to October 2022, we conducted a survey of slaughtered camels, collecting blood, nasal swabs, and tissue samples (n = 454 each; females n = 405; males n = 49) at the Kano abattoir in northwestern Nigeria. We analyzed the sera for MERS-CoV-specific antibodies using the EUROIMMUN® Anti-MERS-CoV ELISA kit and virus neutralization test (VNT). Nasal swabs and tissue samples were tested using an RT-qPCR assay, followed by sequencing. High MERS-CoV antibodies were detected by ELISA (74.8%) and VNT (95.5%). The seropositivity rate was higher in female camels (87.9% by ELISA) compared to male camels (12.0%, P > 0.05). MERS-CoV RNA was detected in 5.0% of nasal swabs and 3.7% of tissue samples. Phylogenetic analysis of the spike protein revealed a 99.9% nucleotide identity with Ethiopian strains, clustering within clade C. These findings confirm exposure of dromedary camels in Nigeria to MERS-CoV, highlighting the need for continuous monitoring using a One Health approach and increased awareness in at-risk groups.

Speaker: Bitrus Inuwa (National Veterinary Research Institute, Vom, Nigeria)

3:30 PM Risk Factors Associated with Mpox Infection: A Case-Control Study in Masaka City and District, Uganda, February–April 2025

Background:
In early 2025, Masaka City was identified as the epicenter of a rapidly growing Mpox outbreak in Uganda, reporting 105 and 125 confirmed cases in February and March, respectively. Preliminary evidence suggested that transmission was driven by close interpersonal contact and specific behavioral and environmental exposures. We conducted a case-control study to identify risk factors for Mpox infection to inform targeted public health interventions.
Methods:
A matched case-control study was conducted between February and April 2025, involving 86 laboratory-confirmed Mpox cases and 172 age- and neighborhood-matched community controls without Mpox history or symptoms. Data were collected using structured questionnaires on demographics, clinical history, behavioral risks, comorbidities, sexual practices, and household structure. Environmental assessments were conducted at case residences. Data were analyzed using Epi Info™ Version 7, and logistic regression was used to estimate crude and adjusted odds ratios (cOR, aOR) with 95% confidence intervals.
Results:
Eighty six Mpox cases were identified, with a mean age of 32 years; the majority were males (52%) and aged 25–34 years 39(45%). Common symptoms included rash (100%), fever (84%), and headache (64%). Multivariate analysis identified four independent risk factors: close contact with individuals with a rash (aOR: 2.5; 95% CI: 1.1–5.8), presence of comorbidities such as HIV or diabetes (aOR: 3.7; 95% CI: 1.6–8.2), male sex (aOR: 3.1; 95% CI: 1.5–6.4), and having multiple sexual partners (aOR: 9.5; 95% CI: 4.5–17.8). Environmental assessments revealed crowding and multifunctional households that impeded isolation.
Conclusion:
Mpox transmission in Masaka was associated with behavioral, clinical, and environmental risk factors. Targeted risk communication, behavior change interventions, early detection strategies, and urban planning reforms are essential to reduce Mpox transmission in high-risk urban settings.
Keywords: Mpox, case-control study, Uganda, outbreak, risk factors, urban health

Speaker: Joyce Owens Kobusingye

3:45 PM → 4:30 PM Coffee Break

4:30 PM → 5:00 PM Keynote II: Thomas Mettenleiter: One Health Governance – from national initiatives to the global pandemic agreement

Convener: Sascha Knauf

5:00 PM → 6:30 PM Session 3: Pandemic Preparedness & Prevention and Social Sciences & Health

Conveners: Sandra Junglen, Maresa Neuerer

5:00 PM SARS-CoV-2 evolution on a dynamic immune landscape

Since the onset of the pandemic many SARS-CoV-2 variants have emerged exhibiting substantial evolution in the virus’ spike protein, the main target of neutralizing antibodies. A plausible hypothesis proposes that the virus evolves to evade antibody-mediated neutralization (vaccine- or infection-induced) to maximize its ability to infect an immunologically experienced population. Because viral infection induces neutralizing antibodies, viral evolution may thus navigate on a dynamic immune landscape that is shaped by local infection history. We developed a comprehensive mechanistic model, incorporating deep mutational scanning data, antibody pharmacokinetics, and regional genomic surveillance data, to predict the variant-specific relative number of susceptible individuals over time. We show that this quantity precisely matched historical variant dynamics, predicted future variant dynamics and explained global differences in variant dynamics. Our work strongly suggests that the pandemic continuously shapes variant-specific population immunity, which determines a variant’s ability to transmit, thus defining variant fitness. The model can be applied to any region by utilizing local genomic surveillance data, allows contextualizing risk assessment of variants and provides information for vaccine design.

Speaker: Sofia Paraskevopoulou (Department MFI, Robert Koch Institute, Berlin, Germany)

5:15 PM Mx-mediated Host Restriction of Emerging Highly Pathogenic Avian Influenza H5N1 Viruses

Since 2022, H5N1 highly pathogenic avian influenza (HPAI) viruses of clade 2.3.4.4b caused unprecedented outbreaks in wild birds and increasing mammal infections, including spill-over into humans. These events raised concerns that H5N1 viruses may further adapt to humans. Indeed, some H5N1 viruses isolated from mammals carry adaptive mutations enhancing receptor binding and polymerase activity. However, efficient human-to-human transmission requires evasion of the human innate immune factor Mx1 (MxA), which restricts replication of zoonotic influenza A viruses (IAVs).
Here, we first investigated (i) if human MxA strongly suppresses H5N1 clade 2.3.4.4b viruses from mammals and (ii) when such H5N1 viruses can escape MxA restriction. Our results show that human MxA strongly suppresses replication of all tested H5N1 viruses in vitro and, to a lesser extent, in MxA-transgenic mice. Using a viral polymerase reconstitution assay, we found that replacing the H5N1 NP with that of a human-adapted H1N1 virus conferred MxA resistance. We further addressed reassortment potential of H5N1 with human-adapted IAVs carrying MxA-resistant NP segments. Using qPCR genotyping, we identified reassortants from co-infections and assessed their replication, polymerase activity and MxA evasion.
Our study reveals molecular barriers limiting transmission of zoonotic H5N1 and highlights genetic constellations possibly enhancing human adaptation, contributing to risk assessment and pandemic preparedness.

Speaker: Dr Jakob Ankerhold (University of Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany)

5:30 PM Towards a One Health Region: Insights from Stakeholders of an Innovation Alliance in Western Pomerania, Germany

The BMBF-funded T!Raum alliance 'One Health Region Western Pomerania' aims to implement One Health principles in the region through transdisciplinary cooperation and knowledge transfer, and to anchor the One Health concept in all decisions by firms, policymakers, and the civil society. The concept of a ‘One Health Region’ is an innovation developed by the T!Raum alliance.
As a key component of the strategic project RegioTransformOneHealth, a broad stakeholder analysis was conducted, including 32 qualitative interviews with regional stakeholders from various sectors, such as veterinary and human medicine, environment, tourism, hunting, agriculture, and forestry. The interviews focused primarily on the necessity for transformation processes to establish a One Health Region in Western Pomerania.
Stakeholders were mainly positive about the establishment of a One Health Region. Necessary transformation processes include strengthening regional value chains, promoting environmental protection initiatives, recruiting qualified young talent for healthcare services, expanding public transport, and increasing cooperation between business and politics.
Collaboration between stakeholders and the T!Raum alliance has the potential to sustainably improve holistic health outcomes, thereby supporting the development of a One Health Region. A preventive and interdisciplinary approach can help mitigate health crises and foster innovative business models in healthcare and regional development.

Speaker: Susan Thomschke (Chair of Economic and Social Geography, University of Greifswald)

6:00 PM Readiness for sampling from the environment for One Health Research: Findings from a Population-based Cohort (MuSPAD) in 2024

Introduction
Environmental sources can harbor zoonotic pathogens, and their sampling – central to the One Health approach – supports research at the human-animal-environment interface. This study aims to assess participants’ readiness to collect environmental samples over a two-year period.
Methods
We analyzed data from a test-focused subcohort (PCR-4-ALL) of the Multilocal and Serial Prevalence Study of Antibodies against (Respiratory) Infectious Diseases in Germany (MuSPAD). Participants’ readiness was assessed via an eResearch system.
Results
Overall, 585/1587 (37%) participants answered the questionnaire on readiness, of whom 445 (80%) were willing to sample their environment and 36 (7%) were uncertain. Readiness to collect water from any water source (e.g. puddles, seawater) was observed in 441 (92%) of the respondents, for any soil sample (e.g. garden, plantation) in 346 (72%), for any arthropods (e.g., fly, tick) in 217 (45%) and for leaf swabs in 307 (65%). Overall, collecting once a month consistently shows the highest proportion of readiness to sample.
Conclusion
Study findings suggest participants are willing to engage in research at the human-animal-environment interface, although arthropod collection may require additional education and support. Since this population is accustomed to regular self-testing, their readiness may be overestimated. Environmental DNA provides insights into local animal and microbial communities, complementing other data sources.

Speaker: Ms Dörthe Meyerdierks (Department of Epidemiology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124, Braunschweig, Germany. Department of Epidemiology, Helmholtz Centre for Infection Research (HZI), Inhoffenstraße 7, 38124 Braunschweig, Germany; Ph.D. Programme "Epidemiology", Braunschweig-Hannover, Germany.)

6:15 PM The One Health Teaching Clinic: An Educational Model for Integrating One Health in Schools

Effective and contemporary educational strategies are essential components for integrating the concept of One Health into (formal) education in schools. In this talk, we present the One Health Teaching Clinic (OHTC) as an innovative educational model that connects future science teachers with One Health experts from medicine, veterinary science, and environmental fields to tackle today’s most pressing One Health research and sustainability challenges. Rooted in the One Health approach, the OHTC promotes interdisciplinary collaboration and practical problem solving in science education. During a 13-week course, student teachers co-create lesson plans with subject-matter experts, linking classroom learning to real-world issues such as pandemics, climate change, and biodiversity loss. The students then run One Health classroom interventions in schools. The OHTC program is running at six universities across Europe and has already involved around 200 future teachers and over 1,000 secondary school students from year 5 to 13. Early results show clear gains in science communication, systems thinking, and education for sustainable development. The OHTC offers a scalable blueprint for preparing the next generation of teachers to become effective change agents at the intersection of formal education and One Health.

Speaker: Ulrich Hobusch (University College of Agricultural and Environmental Education, Vienna, Austria)

5:10 PM → 6:25 PM Session 4: Climate Change & Health

Conveners: Isabelle Kramer, Christiane Klier

5:10 PM Modeling the potential distribution of Wesselsbron, Sindbis, and Middelburg viruses and their vectors in Africa under future climatic and land-use changes

Outbreaks of zoonotic arboviruses originating in Africa have emerged amidst complex ecological changes. Despite sporadic epizootics and human cases of Wesselsbron virus (WSLV), Sindbis virus (SINV), and Middelburg virus (MIV) in Africa, knowledge of associated risks remains insufficient for prevention. Using the Maximum entropy approach, we developed species distribution models that predict the ecological drivers and niches of arboviral diseases in Africa. We used the ecological niches of Aedes circumluteolus and Aedes mcintoshi for WSLV; Culex univittatus and Culex pipiens for SINV; and Mansonia africana and Aedes mcintoshi for MIV. Mosquito species occurrence data were combined with climate and land-use data for current (2015) and future (2021 – 2040) scenarios under two shared socioeconomic pathways of emission and climate projections. Our analyses show that changing patterns in precipitation, especially precipitation in dry and warm seasons, urbanization, human population, livestock density, and climate change exacerbate mosquito expansion and risk for arboviral diseases into new geographic areas. The models predicted hotspots for WSLV, SIV, and MIV in Southern and Eastern Africa and future expansions to the Sahara Desert. Our study highlights the role of climate change in shaping arboviral disease transmission and provides spatial maps to aid targeted surveillance and early outbreak detection.

Speaker: Maureen Nabatanzi (Center for Development Research (ZEF), University of Bonn)

5:25 PM Regional and seasonal variations in the impacts of large-scale teleconnections of the European-North Atlantic region on mosquito abundance in Germany

Several parameters have been used in recent modelling studies to predict the distribution and abundance of arthropod vectors of medical importance. These include several climatological, meteorological and anthropogenic parameters which influence the lifecycle, traits, and flight activities of mosquito vectors. However, the impact of large-scale atmospheric teleconnection patterns in the European-North Atlantic (EUNA) region on mosquito populations is yet to be examined. This study therefore evaluates the potential of EUNA teleconnection patterns such as the North Atlantic Oscillation (NAO), Arctic Oscillation (AO), the Summer East Atlantic (SEA) pattern, East Atlantic Western Russia (EAWR) pattern and the Scandinavian (SCAND) pattern on mosquito abundance in Germany. Using a long-term German-wide mosquito surveillance dataset, time-series regression and temporal-mode principal component analysis (T-mode PCA), we investigated regional and seasonal-specific relationships between EUNA teleconnections and mosquito abundance and diversity in Germany. We found that the EAWR and SEA play a major role in the regional and seasonal variations of mosquito abundance in Germany. Using distributed lag nonlinear models (DLNMs), we found that the strength and mode of the main EUNA teleconnections in the hibernation seasons (winter: lag of 90 days) determine mosquito abundance in the emergence and activity seasons of mosquitoes (e.g., spring and summer). Mosquitoes are highly abundant in the warmest, driest and lowland regions of Germany. These findings contribute to the state-of-the-art on the impacts of natural climate variability on mosquito populations and serves as basis to advance and expand monitoring and forecasting tools of mosquito vectors – an important step to combat the recent surge of mosquito-borne diseases (MBDs) in Germany.

Speaker: Mr Emmanuel Adeleke (Chair of Regional Climate Change and Health, University of Augsburg)

5:40 PM Leptospirosis Occurrence in Europe: Understanding Environmental and Socio-Economic Drivers Using Machine Learning

Leptospirosis is a rodent-borne infectious disease posing a growing global health threat. Human infections occur through contact with environments contaminated by host urine. Recent ECDC reports indicate a rising trend in Leptospirosis cases across Europe, highlighting the need for improved public health measures. Understanding the factors driving leptospirosis occurrence can enhance surveillance and preparedness actions. Here, we investigate environmental drivers of leptospirosis in Europe using a predictive modelling framework. We implemented an XGBoost model to predict the occurrence of at least one leptospirosis case based on temperature, rainfall, environmental, and socio-economic factors, including population density and GDP. We developed the model using the ECDC leptospirosis patient data at the NUTS3 and monthly resolution. The dataset contains 3,868 occurrence and non-occurrence records from 2009 to 2021. We also conducted a SHAP analysis to understand the feature importance. We achieved 75.97% accuracy, 74.56% precision, and 82.93% recall for the model in prediction, indicating a balanced performance in detecting leptospirosis case occurrences and absences. The SHAP analysis revealed that temperature, livestock population, employment, and population density made the most considerable predictive contributions to a case occurrence. Our results contribute to developing spatial risk mapping and prediction to inform healthcare and prevention planning.

Speaker: Omid Airom (1. Heidelberg Institute of Global Health (HIGH), Heidelberg University Hospital, Heidelberg University, Heidelberg, Germany. 2. Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Germany.)

5:55 PM “Heat is a danger to my health even though I said I am used to it”: Qualitative insights of heat among Community Health Workers and Promoters in Kenya

Climate change is one of the most prominent environmental and health challenges of the 21st century. Variations in extreme temperature and weather events are intensifying occupational heat exposure and placing workers at increasing risk of heat-related illness (HRIs) and injury. Healthcare workers especially those in resource-limited, community-based, or mobile settings face significant occupational risks from rising temperatures, yet these challenges remain largely overlooked and insufficiently studied. This qualitative study based on semi-structured face-to-face interviews explores the experiences of Community Health Workers (CHWs) and Community Health Promoters (CHPs) in Kenya, examining how extreme heat affects their personal health, livelihoods, and the delivery of community-based health services. We conducted 41 in-depth interviews with CHWs and CHPs in Mombasa and Tana River counties. Data was managed using NVivo 14 and analysed drawing on tenets of reflexive thematic analysis. We identified a pattern of intersecting vulnerabilities shaped by economic inequality, work conditions, health disparities, climate variability, and gender. We also found that these overlapping factors not only shape the daily experiences of CHWs and CHPs but also constrains their resilience and effectiveness of community health service delivery. Our findings highlight the urgent need for climate-resilient health systems that not only improve the working conditions or protect CHWs and CHPs from extreme heat but also address the structural inequalities such as economic disparities and the challenges of gendered burdens that heighten their vulnerability. By incorporating intersectional approaches to policy and intervention design, our research calls for a more inclusive, equitable response to climate change within the health sector, ensuring that CHWs and CHPs are supported, valued, and equipped to continue their essential work in the face of a changing climate.

Speaker: Dr Kate Baernighausen (Heidelberg Institute of Global Health)

6:10 PM Water Reuse from the One and Planetary Health Perspective

Rising temperatures, changing precipitation patterns and increasing frequencies of drought periods have impacted the water availability in Germany. Especially agriculture is facing challenges due to an increasing demand for irrigation water. The use of reclaimed water, i.e. wastewater that has been treated to be suitable for another use, can help to alleviate the pressure on freshwater resources. However, water reuse comes with risks and potential trade-offs. Remaining pollutants, including contaminants of emerging concern (e.g. pharmaceutical residues, PFAS) as well as human pathogens can enter the food chain, can accumulate in soils, plants or reach groundwater and drinking water resources. Additional water treatment processes can be energy-intensive, contributing to an increase in CO2 emissions. Using the reclaimed water, instead of discharging it to the river, can have adverse impacts on the ecological flow. Water reuse thus requires to be assessed from a “One and Planetary Health” perspective to ensure an appropriate balance between healthy ecosystems, human and animal health, nutrition, socio-economic development as well as climate change mitigation and adaption. This has guided the interdisciplinary discussions on national requirements for water reuse complementing the EU regulation 2020/741 on minimum requirements for water reuse. The negotiations between the different objectives were partially hampered by the lack of a common tolerable risk level.

Speaker: Manuela Helmecke (German Environment Agency (UBA), Dessau, Section II 2.1 General Aspects Water and Soil)

6:30 PM → 8:00 PM Snacks & Poster Viewing I

6:30 PM TBEV in dogs – human behavior leading to an increased infection risk?

Tick-borne encephalitis virus (TBEV) is a zoonotic flavivirus of growing concern within the One Health framework, as its transmission cycle intricately links wildlife, domestic animals, vectors, and human populations. Its circulation is highly focal, depending on competent tick vectors and reservoir hosts in defined natural foci that can remain stable over decades.
In this study, residual serum samples from routine diagnostics were used to investigate TBEV exposure in two canine populations: dogs from an animal shelter located near a well-known TBEV focus active for over 30 years, and a control group from a veterinary clinic without known TBEV exposure. Shelter dogs are regularly walked along routes intersecting the endemic focus, implying increased exposure risk.
So far, 34 samples from shelter dogs and 38 from the clinic have been screened by TBEV-specific RT-qPCR, yielding six positive results, including two from the shelter group. To assess past exposure, ELISA and virus neutralization tests were performed, with seropositive individuals in both populations. Additionally, ticks collected along the shelter’s walking routes tested positive for TBEV RNA, confirming local virus circulation.
These results demonstrate that dogs can serve as valuable sentinels for detecting active TBEV circulation and past exposure. The integration of animal surveillance, vector monitoring, and environmental context illustrates the necessity of a One Health approach to mitigating arboviral risks.

Speaker: Alexander Lindau (University of Hohenheim, Department of Parasitology)

6:31 PM BeoWarn - A Systematic One Health Approach to Early Warning and Crisis Prevention at BVL, Germany

The German Federal Office of Consumer Protection and Food Safety (BVL) is a national risk management authority. BVL fulfils many tasks in the area of food safety. Aims of BVL are transparent risk communication and crisis prevention including early warning in the field of food safety. Since 2015, one of the means for reaching BVL´s goals is BeoWarn, a systematic process that watches different information sources to identify risks and issues with high crisis potential within the remit of BVL´s tasks. The output of BeoWarn includes reports on these risks or issues for risk managers at national, federal and local authorities including food control services.
BeoWarn´s team consists of experts with interdisciplinary qualification backgrounds who continuously monitor various information sources to identify topics with a high crisis potential. Following subjects are covered:
I. Outbreaks and diseases in Germany
II. Risks and issues with crisis potential that occur in Germany
III. Continuous monitoring of already identified risks and issues with a high crisis potential
IV. Hints on what might hit Germany in the future: emerging risks, issues and disease outbreaks in other countries
After several years of BeoWarn´s existence, we consider BeoWarn being a very effective national system for information sharing, networking and for the generation of One Health intelligence.

Speaker: Dr Claudia Reckzeh (Bundesamt für Verbraucherschutz und Lebensmittelsicherheit)

6:32 PM Sleep is a Global Priority: The One Health Perspective

Sleep is a fundamental pillar of health, with a profound impact on mental health and well-being. Yet, the biological mechanisms underlying this universal need remain elusive. We are currently exposed to a wide range of physical (e.g., elevated temperatures, air/noise/light pollution, traffic), social (e.g., socioeconomic disparity, work-related stress, social jet lag and shift work, digital overload, screen exposure), and unhealthy lifestyle factors (e.g., poor diet, physical inactivity, smoking, alcohol, and late caffeine consumption). These exposures disrupt human sleep patterns, posing significant risks to brain and body health. Environmental changes (e.g., heat and air/noise/light pollution) adversely affect the circadian rhythms, feeding, reproduction, activity, and immune function of animals, thereby influencing human sleep during co-sleeping or cohabitating. To assess the impact of these exposome challenges on planet inhabitants’ sleep, we advocate for an integrative “One Sleep Health” model that focuses on an integrated, transdisciplinary link between human and animal sleep with the environmental exposome. This approach incorporates the concept of sleep capital—the cumulative social, economic, and health benefits derived from high-quality sleep—into the global sleep health agenda. By adopting this transdisciplinary lens, which unites neuroscience, medicine, environmental science, and public health, we aim to bridge critical gaps in sleep research and diplomacy.

Speaker: Dr Masoud Tahmasian (Institute of Neuroscience and Medicine (INM-7: Brain and Behaviour), Juelich Research Centre)

6:33 PM Pathogen screening of brown rats from Iran

Norway rats (Rattus norvegicus) are synanthropic rodents associated with a wide variety of pathogens. In Iran, limited information exists on the prevalence and diversity of zoonotic pathogens in commensal rodents. In this study, approximately 100 wild Norway rats from the capital Tehran were screened by RT-PCR and PCR assays for the presence of various bacterial and viral agents.

Five viral and three bacterial agents were detected, including four zoonotic agents. The most prevalent RNA viruses were murine kobuvirus-1 (MuKV1), rat astrovirus (RAstV), and rat hepatitis E virus, with several animals being coinfected with these viruses. Leptospira interrogans DNA was found in about 6% of rats, while Bartonella spp. DNA was found in 14% of rats. Streptobacillus moniliformis DNA was detected in 14.3% of faecal samples. Rattus norvegicus polyomavirus 1 (RnorPyV1) DNA was detected at very low prevalence.

The high prevalence of some zoonotic and animal pathogens may have implications for local communities. Genome characterization of these pathogens provide a better understanding of their genomic diversity in this region and may improve diagnostic capabilities. A future One Health approach, integrating pathogens in humans, animals, and the environment, would allow for a greater understanding of rat-borne zoonotic infection risk in this city.

Speaker: Calvin Mehl (Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health)

6:34 PM Immunolabelling: West Nile Virus in Birds – important hosts and virus amplifier

West Nile Virus (WNV), a zoonotic arbovirus with a mosquito-bird transmission cycle, can lead to severe disease in birds and dead-end hosts such as horses and humans. Its distribution has increased worldwide and the reported WNV cases in 2024 in birds and horses even exceeded the previous years. Recently we described the pathogenesis of WNV lineage 2 in-vivo in geese, showing in particular the early development of not only an encephalitis but also a ganglioneuritis in the enteric nerve system (ENS). Here we aim to clarify more in detail the role of immune cells during the progress of a WNV infection by using several immunohistochemical markers. Therefore, formalin-fixed and paraffin-embedded tissue samples, including ENS and brain, from in total 15 geese infected with WNV-2 and euthanised at five different time points as well as three control geese were stained using CD3 (T-cells), Pax-5 (B-cells), Mum-1 (plasma cells) and Lectin RCA-1 (microglia). Preliminary results show a marked immune reaction in ENS and brain. T cells were present in up to 90% of the plexus of the intestine, already starting 6 dpi and only slowly decreased in the following dpi. A similar process was seen with the encephalitis. These findings are being supplemented with results from naturally infected wild birds. Taken together, the immune mechanisms involved in WNV infections is not yet clarified in its entirety and the study presented here will add new insights in the early pathogenetic progress.

Speaker: Dr Anna Schmitz (Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany)

6:35 PM Subtype agnostic genome reconstruction of the human metapneumovirus using long reads

Conventional workflows for viral genome reconstruction commonly rely on reference-based reconstruction methods. To generate an accurate consensus sequence, these workflows require a reference genome closely related to the target viral strain.

Recent evolutionary processes of the human metapneumovirus (hMPV) include long segmental duplications (DUPs) of over 100 nucleotides in the attachment (G) protein locus. These DUPs introduce sequence complexity that complicates the genome reconstruction, particularly when the sequencing reads are shorter than the duplicated segments. The lengths of DUPs observed in recently emerging hMPV subtypes fall into a “twilight zone” of what can be algorithmically detected from short-read next-generation sequencing data, which typically has an average read length of 150 nucleotides. As a result, recent DUPs in the hMPV genome may remain undetected or inaccurately reconstructed.

We propose a novel computational workflow based on long-read sequencing technologies. Long reads can span entire duplicated segments, facilitating more accurate detection of structural variants such as DUPs. In the case of hMPV, improved DUP detection can lead to more reliable reference strain selection, thereby enhancing the accuracy of genome reconstruction and subsequent taxonomic classification. This project lays the groundwork to establish a robust, routine, and future-proof genomic surveillance during seasonal hMPV epidemics.

Speaker: Jonah Reiner (Department MFI, Robert Koch Institute, Berlin, Germany)

6:36 PM Understanding the urban microclimate-ecosystem nexus to enable holistic climate adaptation in a changing climate (UMEX-HOPE): Implications of landscape structure diversity and climate change in urban-rural microclimates on vector-borne diseases

Urban areas are becoming increasingly vulnerable to the effects of climate change, particularly through altered microclimatic conditions. As part of the Climate Future Labs initiative at the Lower Saxony Centre for Climate Research (ZKfN), the UMEX-HOPE project investigates the links between urban microclimates, ecosystem dynamics, and human health within a One Health framework. It aims to identify how climate adaptation strategies and landscape changes impact health risks such as heat exposure, air pollution, and vector-borne diseases along urban–rural gradients.
As part of the project, we investigate how landscape structure and climate change influence the ecology and transmission risk of mosquito-borne diseases. In the Hanover region and the rural Wedemark area, spatial analyses of fragmentation, habitat connectivity, land use, and land cover are used to identify breeding habitats of Culex and Aedes mosquitoes. Field collections and genetic analyses assess species composition and population structure. Laboratory experiments simulate varying climatic and ecological conditions to study mosquito development and vector competence for West Nile and Chikungunya viruses. Indoor sampling informs household-level risk assessment.
By integrating ecological, spatial, and epidemiological data, we identify high-risk areas and support adaptive public health strategies.

Speaker: Ms Cara Leonie Ebert (University of Veterinary Medicine Hannover, Institute for Parasitology)

6:37 PM Advancing the One Health approach through the integration of digital environmental surveillance into a digital Surveillance Outbreak Response Management and Analysis System (SORMAS)

A growing number of countries face the threat of climate change driven by infectious diseases. The World Health Organization advocates for the One Health approach, which links human, animal and environmental health to enhance surveillance and disease control strategies. In response, a new module for digital environmental surveillance has been developed in SORMAS.
SORMAS is an open-source digital system for epidemic and pandemic preparedness and response. The system allows routine disease surveillance, early detection and outbreak management.
Since its launch in 2015, SORMAS has been recognized as a Digital Public Good and is now used in multiple countries across five WHO regions. It is designed for health professionals involved in epidemic management at all levels - from community health workers to national health authorities and ministries. SORMAS facilitates real-time, multidirectional data exchange within and across borders and supports over 40 infectious diseases in both web and app versions, online and offline.
The environmental surveillance module in SORMAS enables the sampling of water, soil, or air; GPS-based sample tracking; coordination of laboratory transport; assignment of diagnostic procedures; documentation of results and responses and integration of environmental and human data.
This development sets the foundation for fully integrating the One Health approach into SORMAS 2.0, building the next generation of global digital surveillance and outbreak response.

Speaker: Dr Christin Walter (SORMAS Foundation)

6:38 PM Thermotolerant Campylobacter spp. in wild boar and deer in Germany in hunting winter seasons 2018/19-2023/24

Thermotolerant Campylobacter spp. are the leading cause of foodborne bacterial diarrhoea in Europe. Here we analysed caecal and faecal samples (n=672) from 564 freshly hunted wild animals for Campylobacter spp.. A mean prevalence of C. spp. of 77.4% in wild boar (Sus scrofa) and 9.4% in roe deer (Capreolus capreolus) was detected, while C. spp. were absent in red deer (Cervus elaphus, n=52) and fallow deer (Dama dama, n=36).
In wild boar, the most prominent identified species was C. lanienae (n=155), followed by C. coli (n=11), C. jejuni (n=3) and C. hyointestinalis (n=2). Among the 24 isolates from roe deer, 11 were identified as C. vicugnae and 8 C. lanienae, 2 C. hyointestinalis, 1 C. jejuni and 2 yet unknown C. spp. were found.
Whole genome sequencing and core genome (cgMLST) analysis, revealed that C. jejuni and C. coli from wild animals had a very broad phylogenetic distribution. Besides distinct lineages for wild animal isolates, some isolates were found in the same genetic lineages as those from food producing animals. A novel ad-hoc cgMLST scheme for C. lanienae was developed but no shared cluster was observed among wild and food producing animals. However, the number of C. lanienae isolates from the latter was limited.
In conclusion, wild boar and roe deer mainly carry distinct thermotolerant C. spp. that differ from isolates of food producing animals. However, rare exchange of C. spp. strains between wild and food animal populations may occur.

Speaker: Dr Sarah Brüggemann-Schwarze (German Federal Institute for Risk Assessment, National Reference Laboratory for Campylobacter, Unit Food Microbiology, Pathogen-Host Interactions, Department Biological Safety)

6:39 PM High Seroprevalence of Crimean-Congo Hemorrhagic Fever Virus Among Dromedary Camels in Northern Nigeria: Implications for One Health Surveillance

Crimean-Congo Hemorrhagic Fever (CCHF) is a tick-borne viral zoonotic disease that pose a growing public health concern. It is primarily maintained and transmitted by Hyalomma ticks, with livestock such as dromedary camels (Camelus dromedarius) acting as amplifying hosts. In Nigeria, human infections with CCHFV are rarely reported, reflecting limited surveillance and gaps in understanding its epidemiology at the human-animal interface. This study investigated CCHF seroprevalence in dromedary camels across three northern Nigerian states with high levels of human-animal interactions. Using a commercial ELISA kit, we screened 687 sera, with 655 (95.34%) testing positive for anti-CCHFV IgG antibodies. By location, Kano had a seroprevalence of 90.44% (246/272), in Borno 97.74% (259/265), and in Yobe 100% (150/150). These findings demonstrate widespread exposure to CCHFV among camels in these areas. Given the high seropositivity rate in a known amplifying host and the significant human-animal interactions, undetected human infection is plausible. Early clinical signs of CCHF often mimic other endemic febrile illnesses, which might be misdiagnosed. These results underscore the urgent need for integrated One Health surveillance to assess human exposure, improve clinical and diagnostic recognition, and guide evidence-based One Health interventions across Nigeria.

Speaker: Dr Bitrus Inuwa (National Veterinary Research Institute)

6:40 PM Mosquito Communities in Rewetted Peatlands: Balancing Ecosystem Restoration and Vector-Borne Disease Risks

Peatlands are wetland ecosystems that store 44% of terrestrial carbon due to their ability to accumulate organic matter. However, 15% of peatlands worldwide are drained or degraded, threatening the stability of carbon stocks and other ecosystem services that depend on water-saturated conditions. Rewetting peatlands is therefore a key climate mitigation measure. Nevertheless, wet peatlands create ideal breeding habitats for mosquitoes. Although this includes vectors of severe pathogens, our knowledge of the temporal and spatial effects of rewetting measures on the distribution of mosquitoes and mosquito-borne pathogens is limited.
To identify different species compositions and unravel driving mechanisms, we set up 15 CO2-baited traps in a peatland complex in north-eastern Germany, sampling biweekly over 24-hours periods. Sampling sites included rewetted and drained peat soils, drainage pumps and nearby settlements. Rank abundance curves showed similar dominance structures in settlements and rewetted sites, with the most even mosquito communities at pumping stations. Rényi diversity profiles revealed no significant differences in overall diversity, but ordination analysis distinguished two main mosquito communities: one in settlements and one at rewetted sites. Other sites did not host unique assemblages. These results improve our understanding of mosquito ecology in rewetted peatlands and can help mitigate health risks, supporting the acceptance of wetland restoration efforts.

Speaker: Patrick Gutjahr (Friedrich-Loeffler-Institut)

6:41 PM Four years of nationwide monitoring of Culicoides (Diptera: Ceratopogonidae) on livestock farms in Germany, 2019-2022

Biting midges of the genus Culicoides are vectors of economically important livestock arboviruses, including bluetongue virus (BTV) and Schmallenberg virus (SBV). Repeated outbreaks of bluetongue disease and ongoing SBV circulation in Central Europe highlight the need for long-term surveillance. To address this, a Germany-wide monitoring programme was conducted on livestock farms, collecting year-round data on Culicoides activity from 2019 to 2022. UV-light traps were operated weekly for 24 hours in, or close to, livestock housing. Over 1.44 million biting midges were collected and morphologically identified. With 76% of all individuals collected, potential vectors of the Obsoletus Group dominated across all years. Culicoides specimens were captured in all months, with low numbers from December to March. Seasonal activity began in early April, followed by consistently high capture rates from late May to July and a secondary rise in September and October. Peak activities varied across years and sites, reflecting weather-related and local factors. Notably, the year 2021 contributed 43% of the total catch. Across all years, blood-fed females were mainly found from April to October, with almost none in January and February. These findings provide a comprehensive baseline for Culicoides occurrence and activity in German livestock holdings and highlight the importance of multi-year, multi-site monitoring to determine seasonal dynamics under changing environmental conditions.

Speaker: Ms Anja Voigt (Leibniz-Centre for Agricultural Landscape Research)

6:42 PM Hidden diversity of rinderpest virus uncovered in historical pathology collections

Rinderpest virus (RPV; Morbillivirus pecoris) and measles virus (MeV; Morbillivirus hominis) are RNA viruses that belong to the Paramyxoviridae family which have had a major impact on livestock and human health. RPV caused the death of billions of cattle, with fatality rates reaching up to 90%, until its eradication in 2011. MeV causes measles in humans; a disease that, despite the availability of a vaccine since the 1960’s, still leads to approx. 110,000 deaths annually. RPV and MeV are each other’s closest relatives. It is believed that MeV emerged in humans from a cattle-infecting ancestor of RPV. Using historical measles specimens to recover MeV genomes and applying tailored phylodynamic methods, we recently suggested that MeV may have emerged as early as 600 BCE, correlating with the rise of big cities.
Here, we intended to reassess this notion by investigating the evolution of RPV across a century of control measures by generating ancient RPV genomes from historical specimens. We applied pathogen genomic approaches to analyze 41 pathology specimens, sourced from three different pathology collections.
While we have not fully completed this study, our preliminary phylogenetic analyses already revealed that our RPV sequences fall outside of the known diversity of RPV, highlighting previously unrecognized viral diversity.
We expect that this project will ultimately unveil key elements of the evolution of morbilliviruses in their human and domestic hosts.

Speaker: Lilli Gralla (Department of Pathogen Evolution, Helmholtz Institute for One Health, Greifswald, Germany)

6:43 PM Borna disease virus 1 infection in organotypic hippocampal slide cultures from adult rats

Borna Disease Virus 1 (BoDV 1) is a zoonotic and neurotropic virus that causes fatal non-suppurative encephalitis in humans, horses, sheep, and alpacas. The white-toothed shrew (Crocidura leucodon) has been identified as a natural reservoir host, harboring a persistent infection without developing neurological impairments. For infection studies, the adult rat serves as a suitable model for studying inflammation in dead-end hosts.
Viability of organotypic hippocampal slice cultures of adult rats was analyzed by LVE/DEAD immunofluoresence staining, LDH assay, PCR of housekeeping genes and morphologic integrity.
In a second step, viral spread, infection patterns, and the local innate immune response were analyzed using immunofluorescence and qPCR to assess viral load.
OHCs were susceptible to infection while maintaining tissue integrity for up to 28 days in culture. Viral distribution was uniform across hippocampal regions, but viral load decreased between days 3 and 7 post-infection (p.i.) before increasing between days 7 and 21 p.i. These results demonstrate that OHCs provide a valuable model for studying viral persistence, distribution, and load in adult rats.

Speaker: Maximilien Lépine (Institute of Veterinary Pathology, Justus-Liebig-University Gießen)

6:44 PM The Discovery of the Lyon IARC Polyomavirus: A Zoonotic Pathogen with Oncogenic Potential in Humans and Cats?

The Lyon IARC polyomavirus (LIPyV), discovered in 2017, was detected as the fourteenth human polyomavirus in saliva and skin samples of healthy individuals (Kamminga et al. 2023). LIPyV exhibits a transforming effect on human primary cells, suggesting potential oncogenic properties (Venuti et al. 2022). LIPyV has also been detected in fecal samples from cats suffering from diarrhea (Li et al. 2021; Fahsbender et al. 2019). The detection of specific antibodies targeting the major structural protein of LIPyV (LIPyV-VP1) in both feline and human serum samples points towards possible zoonotic transmission (Kamminga et al. 2023).
While documented in France, the USA, Finland, and the Netherlands, LIPyV has not yet been reported in Germany. The research project aims to detect and isolate LIPyV in cats in Germany and to determine the prevalence of specific antibodies in human and feline serum samples. Another key objective is to explore a potential association between LIPyV's detection and specific disease symptoms including brain tumors.
To address these questions, a comprehensive screening of feline and human samples is planned. A specific indirect enzyme-linked immunosorbent assay (ELISA) against the LIPyV-VP1, as well as a specific real-time polymerase chain reaction (qPCR) for LIPyV, are currently under development. Virus-positive samples will be further characterized using next-generation sequencing and will subsequently be isolated in a cell culture.

Speaker: Ms Johanna Reiff (Institute of Virology, Faculty of Veterinary Medicine, Leipzig University)

6:45 PM Blood feeding preference of Culex pipiens in the West Nile virus endemic metropolitan area of Berlin

West Nile virus (WNV) is a mosquito-borne arbovirus endemic in Berlin since 2018, that replicates in an enzootic cycle between Culex pipiens and birds as reservoir hosts. Little is known of Culex pipiens host feeding preference in urban areas, especially with respect to the bird species acting as the main amplification host(s) for WNV.
To gain insight into host feeding preferences, the blood-fed specimens of a collection of about 100,000 mosquitoes collected in 2023/24 will be analyzed. A subset of 229 blood-fed mosquitoes were analyzed so far using PCR targeting the vertebrate-specific cytochrome c oxidase subunit I (COI) gene, followed by Sanger sequencing. In total, 36 vertebrate host species were identified. The 29 non-Culex-specimens were found to have mainly fed on mammals (96.4%, humans, foxes, squirrels, mice), whereas 89.5% of the 200 Culex mosquitoes had fed on birds and only 10.5 % on mammals. In total, 27 avian hosts were identified, which were mainly blackbirds (22.5%), pigeons (20%), sparrows (13.5%), robins and great tits (each 7%). One Culex pipiens that had fed on a common redstart was tested positive for WNV.
WNV transmission is dependent on vector feeding on competent amplification hosts. The identification of the bloodmeal sources of WNV vectors is thus important to identify the key players of the enzootic WNV amplification cycle and of hotspot areas, where human and bird infection risks are high.

Speaker: Romy Schönberger (Charité - Universitätsmedizin Berlin)

6:46 PM Searching for mosquito-borne pathogens in mosquitoes (Diptera: Culicidae) collected in northeastern Germany

Globalization as well as climatic and environmental changes support the global spread of vectors and vector-borne diseases. Europe has recently been facing a rise in mosquito-borne diseases, following improving conditions for both mosquitoes and mosquito-borne pathogens. To monitor the circulation of mosquito-borne disease agents, zoos and wildlife parks have increasingly been recognized as appropriate early warning sites. Their structurally diverse habitats, the presence of numerous water containers, and a high density and variety of vertebrate blood host species, provide favourable conditions for both mosquito development and pathogen circulation. Therefore, BG sentinel traps were set up at eleven zoos and wildlife parks to study mosquito populations and associated pathogens in northeastern Germany in summer 2024. Among a total of around 4,600 collected mosquitoes, 14 species were identified, mainly from the Culex pipiens complex (ca. 3,700 individuals). Preliminary RT-PCR analyses of single mosquitoes or pools with up to ten specimens resulted in the detection of viruses in that species complex: Sindbis virus in a single mosquito from one location, West-Nile virus in two pools from one location and Usutu virus in three pools from three locations. To obtain information about virus overwintering in mosquitoes, over 34,000 mosquitoes were collected in 130 dungeons, bunkers and cellars in northeastern Germany in the winter 2024/2025. Mosquito identification revealed six taxa but virus screening is still pending.

Speaker: Nihal Telli (Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit)

6:47 PM Using environmental samples to study genomic diversity of human viruses

Viruses infecting humans can not only be found in the human body, but in a range of environmental samples from our surroundings. This includes indoor surfaces such as handrails or door handles, air within closed spaces, or sewage. While quantitative detection of viral pathogens in such samples is established for decades, the comprehensive exploration of the genomic therein is a much more recent development, driven by the still dropping costs of high-throughput sequencing.
In our previous study, we analyzed total RNA sequencing over 17 months from a wastewater treatment plan in Germany along with published, comparable data from other continents. This approach allowed enabled the temporal and geographic tracking of viral variants down to individual genome positions. Currently, we are focusing on an in depth investigation of the genomic diversity within enteroviruses and noroviruses in samples from Germany and internationally. Here, we present open questions and directions for future research.

Speaker: Emanuel Wyler (Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Berlin, Germany)

6:48 PM Public Health Bioinformatics: establishing the toolkit for the integrated genomic surveillance of bacterial pathogens

The SARS-CoV-2 pandemic highlighted the importance of how continuous molecular monitoring remains pivotal for enabling public health interventions. The integrated genomic surveillance (IGS) aims to provide a system in Germany to support both federal and local health authorities across multiple groups of public health relevant pathogens. To address this bioinformatically, we have developed a toolkit of modular computational workflows to enable the genomic assessment of bacterial pathogens.

One major challenge represents the selection of scientific software for inclusion within a routine surveillance system. Many available solutions have been developed for research projects, limiting their applicability for routine public health bioinformatics. This includes limitations in stability, efficiency, speed and license usage, but also the lack of a continuous maintenance strategy.

Here, we present the IGS bioinformatics toolkit, consisting of standardized, curated workflows to address the needs for a continuous surveillance of public health relevant pathogens. The toolkit is open-source and encompasses methods from assembly and profiling, to clustering and visualization of bacterial genomes. These tools may also be utilized for the analysis of additional sources within the One Health framework, including foodborne or veterinary data sets. Our toolkit hereby lays the foundation for performing routine bioinformatic analyses within the scope of the IGS for bacterial pathogens in Germany.

Speaker: Dr Silver A. Wolf (Genome Competence Centre (MF1), Robert Koch Institute, Berlin, Germany)

6:49 PM Detection and Isolation of Mycobacterium avium subsp. paratuberculosis in Intestinal Lesions of Slaughtered Sudanese Small Ruminants: Challenges for Public Health and Food Safety

Mycobacterium avium subsp. paratuberculosis (MAP) is suspected to play a role in Crohn's Disease in humans, a gastrointestinal inflammation similar to paratuberculosis (PTB) in animals. Our reports that over 40% of patients with gastrointestinal disease complaints in the Sudan were positive for MAP and that the disease is present in all ruminant animals raised questions about the possible routes of MAP transmission to humans. Therefore, this study, conducted at Albaraka slaughterhouse (Omdurman) from October to December 2021, aimed at investigating MAP in intestinal lesions of slaughtered small ruminants. The viscera of 500 slaughtered animals were examined for gross lesions and samples were collected for further histopathology, bacteriology and molecular biology investigations. Gross lesions (N=31) observed were mainly enlargement of mesenteric lymph nodes, MLN, (N=30) and thickening of the ileum mucosa (N=1). Histopathological lesions including lymphoid tissue proliferation with villous atrophy in the small intestines and cortical lymphoid hyperplasia in the MLN were detected in 12 samples among which 4 were positive for acid-fast bacilli (AFB) in tissue smears stained with Ziehl-Neelsen (ZN) staining and for MAP DNA as well. MAP was isolated from 3 samples including one AFB- positive with no histopathological lesions. Overall, the samples that tested positive for MAP through real-time PCR and culture were also AFB-positive, with a positivity rate of 33% (4 out of 12). Detection and isolation of MAP in slaughtered small ruminants in the Sudan emphasizes public health concerns, especially in relation to food safety. These findings highlight the importance of routine MAP screening using ZN staining of direct tissue smears as a quick and simple method, especially at critical points, like slaughterhouses, to prevent food supply chain contamination and mitigate potential public health risks.

Speaker: Ms Sanaa Idris Mohamed (University of Khartoum)

6:50 PM Reinventing the Rodent-Borne Pathogen Network: From Past Achievements to Future Directions

Rodents and other small mammals are key reservoirs for numerous pathogens, including zoonotic agents transmissible to humans, animal pathogens as well as infectious agents specific to small mammals. The transmission dynamics of these pathogens are shaped by complex biotic and abiotic environmental factors and reservoir functions such as genetics, necessitating a holistic, interdisciplinary approach aligned with the One Health framework, which integrates human, animal, and environmental health.
Since 2004, the Rodent-Borne Pathogen Network has established itself as a stable and collaborative platform for the study of rodents and small mammals across Europe focussing mainly on Germany. By fostering international and cross-sectoral partnerships, the network has facilitated the collection and analysis of extensive samples from pet animals and diverse wildlife ecosystems, advancing our understanding of small mammals as reservoirs of both zoonotic and non-zoonotic pathogens. It has also played a critical role in developing new methodological tools for pathogen surveillance and in translating research findings for use in public health, veterinary services, and among other relevant stakeholders.
The network has contributed to key epidemiological insights, such as the ecology of Puumala orthohantavirus and Borna disease virus 1, and has enhanced knowledge of wild rodent community structure and their associated pathogen diversity. Its investigations have also supported the detection of “novel”, so far unknown and (re)emerging pathogens and helped to elucidate evolutionary and ecological patterns in host–pathogen interactions and disease outbreaks.
Recent global developments—including technological advances, environmental change, and increased zoonotic spillover risk highlighted by the COVID-19 pandemic—underscore the need to expand the network’s scope. This presentation introduces core concepts and objectives for its next phase, with a focus on enhancing ecological pathogen surveillance and harnessing emerging analytical tools to better understand and mitigate rodent- and other small mammal-associated disease risks.

Speaker: Anna Obiegala (Institut für Tierhygiene, Universität Leipzig)

6:51 PM Legionella Genotype Map – Statewide Genomic Surveillance of Environmental Isolates

Background:
Despite their significant public health relevance, the epidemiological links between environmental Legionella sources and human infections remain poorly defined. This is due to limited strain-level resolution in standard detection methods and a lack of harmonized genomic surveillance data across environmental compartments. With climate change promoting conditions conducive to Legionella growth and transmission, the need for a robust molecular surveillance system is growing.
Objective:
To establish a genomic framework for routine environmental monitoring and genotyping of Legionella spp. in Lower Saxony using whole genome sequencing (WGS), in order to develop a state-level "Legionella Genotype Map" as a tool for outbreak preparedness and source attribution.
Methods:
Up to date around 100 environmental Legionella pneumophila (n = 93) most common and clinically relevant pathogenic Legionella species isolates from diverse geographic regions and water types across Lower Saxony. The isolates have already been collected and cultivated with high quality standard taxonomically verified using short-read sequencing (Illumina) and long-read sequencing (Oxford Nanopore), enabling high-resolution hybrid genome assemblies. Subsequent analyses include resistome/pathogenicity profiling using a custom-built bioinformatics pipeline in collaboration with the University of Duisburg-Essen and Universitätsmedizin Essen.
Results:
The survey sequencing results using short-read sequencing and WGS for core genome sequence multilocus typing (cgMLST, Ridom Seqsphere) analysis of Legionella pneumophila isolates (n = 93) showed different complex types (>50, CT) (Fig.). However, there were clustering samples resulting in clusters (>10), which gives a first look on surveillance data across environmental compartments as a tool for outbreak preparedness and source attribution.

Speaker: Ricarda Schmithausen (Niedersächsisches Landesgesundheitsamt (NLGA))

6:52 PM Nontyphoidal Salmonella transmission reservoirs in sub-Saharan Africa: a genomic assessment from a One Health Perspective

Background: Nontyphoidal Salmonella causes more than 1.2 million annual deaths worldwide, the majority in resource-limited countries such as sub-Saharan Africa. Nontyphoidal Salmonella have also become increasingly resistant to antibiotics and are the most frequent cause of bacteraemia in sub-Saharan Africa. Recent data suggests that this typically livestock- associated pathogen has genetically developed and adapted to different hosts and environments, proposing anthroponotic transmission.
Methods: Within this study, we collected Salmonella from humans (stool and blood), animals and the environment (dust and soil), in Tanzania and in Ghana. Strains were identified by biochemical methods and confirmed using the VITEK 2 System. Serotyping and antibiotic susceptibility testing was performed. Further, isolates were subjected to sequencing using a NextSeq 500 Illumina sequencer.
Results: 9,099 samples were collected. From these, 222 Nontyphoidal Salmonella were identified comprising 58 serovars. The highest level of resistance was in humans with fluroquinolone resistance on the increase and multidrug resistance highest in isolates from blood cultures (24%, n/N=11/46). Of the invasive strains, MLST analysis confirmed the serovars and sequence types S. Typhimurium (ST313/ST19) being most common followed by S. Enteritidis (ST11/ST1479) and S. Dublin (ST10). A sequence type overlap amongst humans and livestock or environmental strains was detected for ST19.
Conclusions: Our study demonstrates a broad serovar distribution of Salmonella from livestock and the environment not typically associated with human infections. The substantially high level of multidrug resistance and emerging fluoroquinolone resistance seen in the invasive nontyphoidal Salmonella poses a challenge to current treatment strategies. Interestingly, we found ST19 more common in invasive human disease but also prevalent in samples from livestock compared to ST313, only seen in human samples. These findings strongly support the hypothesis of anthroponotic transmission of ST313 but not of ST19 in sub-Saharan Africa.

Speaker: Denise dekker (BNITM)

6:53 PM Development of a Nextflow Pipeline for Structural Variant Detection and Evaluation in German Mycobacterium tuberculosis Samples

Broadly utilized in bacterial pathogen surveillance, enabling infection chain and outbreak investigations, are clustering approaches that employ core genome multi-locus sequence typing (cgMLST) to define pairwise genetic distances.
For the Mycobacterium tuberculosis complex (MTBC), structural variants (SVs), particularly regions of difference (RDs), which are large-scale insertions and deletions relative to the H37Rv reference genome, have been described as stable phylogenetic markers. However, the presence of such structural variants may interfere with cgMLST-based typing. Specifically, deletions that overlap cgMLST loci can introduce missing values and skew genetic distances between isolates, justifying the exclusion or masking of certain cgMLST loci.
To investigate this issue, we designed Tubrd, a Nextflow-based workflow to evaluate the presence of known RDs and to detect novel structural variants from short-read sequencing data. We analyzed 8,000 MTBC samples collected within the scope of integrated genomic surveillance (IGS).
We anticipate that our results will stratify by lineage, improving the accuracy of molecular epidemiology in TB surveillance. Application of this pipeline to a selection of 100 MTBC isolates from IGS revealed that ~3% of established RDs impact cgMLST profiles, along with 20 novel SVs across the dataset that show a similar effect. These initial findings highlight the importance of assessing structural variation to enable accurate genome-based clustering.

Speaker: Caroline Roschek (Genome Competence Centre (MF1), Robert Koch Institute)

6:54 PM VirusWarn: Mutation-based prioritization of concerning SARS-CoV-2 and Influenza virus variants from isolate and wastewater sequencing data

The rapid evolution of respiratory viruses is characterized by the emergence of variants with concerning phenotypes that are efficient in antibody escape or show high transmissibility. This necessitates timely identification of such variants by surveillance networks to assist public health interventions.
Here we introduce VirusWarn, a comprehensive system designed for detecting, prioritizing, and warning of emerging virus variants from large genomic datasets. VirusWarn uses both manually-curated rules and machine-learning (ML) classifiers to generate and rank pathogen sequences based on mutations of concern and regions of interest.
Validation results for SARS-CoV-2 showed that VirusWarn successfully identifies variants of concern in both assessments, with manual- and ML-derived criteria from positive selection analyses. Although initially developed for SARS-CoV-2, VirusWarn has also been adapted to Influenza viruses and provides a robust performance, integrating a scheme that accounts for fixed mutations from past seasons. In addition, it features HTML reports that provide detailed results with searchable tables and visualizations, including mutation plots and heatmaps.
Because VirusWarn is written in Nextflow, it can be easily adapted to other pathogens, demonstrating its flexibility and scalability for genomic surveillance efforts. We are now applying VirusWarn to wastewater sequencing data, in order to provide timely surveillance of emerging variants on a broad scale.

Speaker: Christina Kirschbaum (Robert Koch Institute)

6:55 PM Genomic surveillance of Dengue virus in Central Côte d’Ivoire: Insight from the 2024 outbreak

Dengue virus (DENV) is a significant public health concern in Côte d'Ivoire, reflecting broader trends across West Africa. Despite the clear public health burden, the true extent and diversity of DENV strains circulating in Côte d'Ivoire remain poorly characterized due to insufficient diagnostic capacity and a lack of genomic data. Understanding the genomic diversity of Dengue virus is crucial for public health interventions and epidemic preparedness.

As part of the Public Health Actions for Côte d’Ivoire (PAcCI) project, operating at the Centre Hospitalier Universitaire (CHU) de Bouaké in the center of the country, we investigate the genetic diversity of circulating Dengue virus strains in Central Côte d’Ivoire with the aim of tracing introductions and identifying mutations potentially associated with transmission or pathogenicity.

Between May and August 2024, blood samples were collected from 172 individuals with suspected dengue infection residing in Bouaké and its surrounding areas. Real time PCR screening identified 40 positives cases. Whole-genome sequencing of 37 positive samples was performed using an amplicon-based approach with a pan-serotype primer scheme, implemented on the Oxford Nanopores Technology Minion Mk1b platform. Sequencing libraries were prepared using a native barcoding ligation kit. Basecalling and demultiplexing were performed using the Dorado software. Genome reconstruction was conducted using a customized Nextflow workflow incorporating the ARTIC pipeline. Laboratory analyses were conducted directly at the CHU Bouaké’s laboratory. Phylogenetic analyses were conducted to characterize serotypes, genotypes and viral lineages.

Among sequenced samples, Dengue virus serotype 3 (DENV1) was detected in 50%, DENV2 in 25% and DENV1 in 25 % of cases. There was no detection of Dengue virus serotype 4 (DENV4). A total of 32 samples yielded eight DENV1, eight DENV2 and sixteen DENV3 partial genomes (genome coverage ranging 57-98%). Further analyses including multiple sequence alignment and phylogenetic inference are currently underway to assess genotype distribution, determine the phylogenetic placement of Ivorian strains within the context of global DENV diversity, and investigate evidence for new introductions, local evolution, as well as the presence of unique or rare mutations.

This pilot study is the first of its kind to set up a sequencing workflow for whole genome amplification of dengue virus in an Ivorian laboratory. The preliminary findings underscore a multi-serotype circulation of Dengue virus during the 2024 outbreak in Central Côte d'Ivoire. This study provides a critical foundation for the implementation and continuous genomic surveillance in Côte d'Ivoire to track dengue virus circulation dynamics for an efficient epidemic preparedness and response.

Speaker: Dr Arsene Zongo (Center for International Health Protection, Robert Koch Institute, Berlin, Germany)

6:56 PM The Role of Free-Living Amoebae in Supporting the Persistence of Atypical Brucella spp. in the Environment

Classical Brucella are host-adapted, zoonotic pathogens that replicate within macrophages of their hosts. Recently, atypical Brucella strains have been isolated from rodents, amphibians and soil. These Brucella isolates are genetically more similar to environmental Ochrobactrum spp., raising questions about their niches and zoonotic potential. This study explores whether free-living amoebae, which share phagocytic traits with macrophages, serve as reservoirs for these atypical Brucella.
We tested B. microti, three amphibian-derived Brucella isolates and two Ochrobactrum isolates for growth under different abiotic factors, as well as their interactions with amoeba (Dictyostelium discoideum and Acanthamoeba castellanii). All tested bacteria tolerated acidic culture conditions. The temperature optimum for B. microti and Ochrobactrum was at 28°C, but it varied for the other isolates. Preliminary data from macrophage infection assays confirmed intracellular replication of B. microti and amphibian-derived isolates. The latter resisted phagocytosis on an amoeba monolayer. In buffer, two of the amphibian-derived isolates showed increased proliferation in co-cultures with D. discoideum.
These findings suggest that atypical Brucella benefit from amoebae and thus might support their persistence in the environment. The ability of atypical Brucella to withstand acidic conditions, to adapt to lower temperatures, and to replicate in macrophages supports the hypothesis of a dual lifestyle in environmental and host-associated niches.

Speaker: Lisa Remus (Federal Institute for Risk Assessment)

6:57 PM Impervious Density and Borrelia burgdorferi s.l. Seropositivity within the German National Cohort (NAKO)

Introduction
The environment influences tick density and activity. We investigated the effect of varying buffers around the residential address on the association between impervious density and Borrelia burgdorferi s.l. seropositivity in NAKO (German National Cohort) participants.
Methods
We included 14,195 participants from four NAKO study centers. Impervious density was dichotomized indicating the presence (<0.3) or the absence (≥0.3) of greenspace at home addresses during baseline examination (2014 – 2019). Utilizing an enzyme‐linked immunosorbent assay (ELISA) B. burgdorferi s.l. antibodies (IgG) were measured in blood samples. Previous analyses showed associations for age, sex and migration background. We performed adjusted hierarchical models with the study centers as random intercept.
Results
We detected an OR of 1.85 (95%-CI 1.39 – 2.48) for a 100 m buffer of less imperviousness compared to higher impervious density, of 1.59 (1.23 – 2.05) for a 250 m buffer, of 1.52 (1.22 – 1.90) for a 500 m buffer, of 1.26 (1.03 – 1.55) for a 1000 m buffer and of 1.01 (0.81 – 1.25) for a 5000 m buffer. When stratifying for the degree of urbanization the association between imperviousness and IgG-seropositivity was significant for the urban subgroup and the 100 m buffer only (OR 1.60, 95%-CI 1.05 – 2.44).
Conclusion
Our findings of possibly adverse effects of less imperviousness (in a 100 m buffer) contrast with the potentially beneficial effects of green spaces, e.g. on mental health.

Speaker: Philine Betker (Department of Epidemiology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany.)

6:58 PM Borrelia burgdorferi s.l. genospecies and genotypes in Ixodes ricinus ticks from different neuroborreliosis-risk areas in Denmark

Neuroborreliosis (NB), the most severe Lyme borreliosis form, is linked to Borrelia garinii and B. bavariensis. However, it is unclear if all genotypes cause disease. The database for Borrelia multilocus sequence typing (MLST) shows a higher diversity of sequence types (STs) in ticks than in humans, suggesting that not all STs cause symptoms. Our study explores Borrelia prevalence, genospecies, and ST diversity in three NB risk area types: significantly high, non-significant (medium risk), and significantly low.
In 2023, ticks were collected from the vegetation on Funen, Denmark, in high, medium, and low NB risk areas, based on reported incidence data from Odense University Hospital. Tick DNA was tested for Borrelia via qPCR and further analyzed using MLST. After sequencing, the results were compared to the MLST database.
A total of 2007 I. ricinus ticks were collected. Nymphs (87.3%) were the dominant life stage. Borrelia DNA was found in 11.7% of ticks (n=234), with a slightly higher prevalence in medium risk areas (13.9%) than in high and low risk areas (10.4% each). So far, 46 samples out of 85 with Ct ≤ 37.5 have been sequenced, revealing 6 genospecies, B. afzelii, B. bavariensis, B. burgdorferi s.s., B. garinii, B. spielmanii, and B. valaisiana, belonging to 41 different STs (26 pre-existing and 20 with novel allele combinations). 11 STs found in our study showed known pathogenic profiles. They were found in all three NB risk area types. Three of them were detected for the first time in ticks.
Further analysis of this ongoing study will be presented at the conference. This work has been supported by the German Academic Exchange Service (DAAD).

Speaker: Dr Nina Król (Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, Germany; Clinical Center for Emerging and Vector-Borne Infections, Odense University Hospital, Denmark; Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark)

6:59 PM Virus genome reconstruction for the integrated genomic surveillance in Germany using Nextflow

Genomic surveillance is crucial for monitoring pathogens of public health significance, focusing on the detection of changes in the pathogens’ genomes, such as new mutations and variants. Prompt detection assists outbreak analytics while revealing variants with increased transmissibility or virulence. The COVID-19 pandemic has underscored the necessity for high-quality genome sequences for effective surveillance.
At the Robert Koch Institute, we are harmonizing our various virus genome reconstruction pipelines into a single multi-virus reconstruction pipeline, Omnifluss, enhancing maintainability and sustainability. We are utilizing the workflow manager Nextflow to ensure scalability, portability, and reproducibility. At the same time, we adhere to nf-core standards for community-driven best practices, guidelines for developing, testing, and curating Nextflow pipelines.
The main processes of Omnifluss are read preprocessing and quality control, variant calling and consensus generation, and post-reconstruction analyses. As a prime example of Omnifluss' utility, we have implemented an Influenza reconstruction pipeline for Illumina short reads, tailored to meet the requirements of Influenza-specific sequencing protocols and the standards set by pathogen experts at the Robert Koch Institute. Its modular architectural structure uses pathogen-specific configurations defining pathogen-specific tools and parameters.

Speaker: Marie Lataretu (Genome Competence Center (MF1), Robert Koch Institute, Berlin, Germany)

7:00 PM Influenza virus detection in wastewater: Method evaluation and relevance for One Health surveillance

Influenza viruses (FLUV) pose a significant threat to global health and require comprehensive surveillance approaches. Although wastewater-based surveillance (WBS) has proven valuable for pathogen monitoring at the community level, its application to FLUV remains methodologically under-explored.
We evaluated the performance of various method combinations that included virus concentration and RNA extraction for the detection of FLUV RNA in municipal wastewater. Using genomic RNA and spiked wastewater samples, we assessed the sensitivity of the protocols and their efficiency in terms of recovery.
Our results demonstrate substantial differences in detection performance depending on the combination of methods used. The best-performing method (PureYield™ filtration + Maxwell® extraction) achieved recovery efficiencies of up to 80% and enabled detection estimated two weeks earlier compared to protocols exhibiting less sensitivity. These differences are critical when targeting low-abundance pathogens like FLUV. Delays in detecting the onset of a seasonal FLUV wave due to employment of less sensitive method combinations could significantly impair early warning capabilities in WBS. Our findings highlight that rigorous method evaluation is essential not only for reliable quantification but also for timely public health response. Similar challenges are likely to apply to other infectious agents, emphasizing the need to integrate validated protocols into One Health surveillance frameworks.

Speaker: Dr René Kallies (Umwelbundesamt)

7:01 PM Association of land-use with genetic and morphological variability of the Culex pipiens complex in Germany

Mosquitoes of the Culex pipiens complex are relevant vectors of West Nile Virus, which has been locally detected in Germany since 2018. Environmental changes, including land-use modifications and climate change, may influence genetic and morphometric traits of mosquito populations, potentially affecting their fitness and vector competence.

This study examines association between environmental factors (land-use, temperature, latitude), genetic variability, and wing characteristics (shape, centroid size) of Culex pipiens s.s. populations.

Up to 20 female mosquito specimens from 23 sites across Germany were used. Wing shape and size were assessed using landmark-based morphometric methods, and genetic variability was examined via mitochondrial COI gene sequencing. Wing shape showed weak associations with latitude and land-use types (p<.05, R² < 2%), and tree cover had a minor effect on centroid size (R² = 1.4%). Genetic variability was low (π = 0.49; Hd = 0.15). Haplotype analysis assigned 341 specimens to biotype pipiens and 8 to molestus. A negative Tajima’s D (-2.05) indicated population expansion. No correlation was observed between wing shape and genetic variability.

The results indicate limited genetic variability of the Culex pipiens s.s. populations. Although associations between environmental factors and morphology were measured we conclude that these influences are minor and that Culex pipiens s.s. populations in Germany exhibit a highly stable population structure.

Speaker: Ms Joy Saathoff (Bernhard-Nocht-Institut für Tropenmedizin)

7:02 PM Multiplexing Antigens to Approach the Complexity of Orthonairovirus Serology

Climate change affects the distribution of vector-borne diseases. Orthonairoviruses are significant tick-borne pathogens affecting both humans and livestock. Serosurveillance is a critical tool for indirect detection of virus circulation, and has traditionally focused on anti-nucleoprotein (N) antibodies. However, the close antigenic relationship among orthonairoviruses N proteins often causes serological cross-reactivity, complicating accurate diagnosis. In this study, the glycoprotein GP38 was therefore evaluated as an alternative antigen.

We used field and experimental sera from the respective target species, i.e. humans and sheep, which were formerly infected with Crimean–Congo hemorrhagic fever virus (CCHFV) or Nairobi sheep disease virus (NSDV) to assess seroconversion and cross-reactivities between antigens of both viruses, first using an ELISA format. Additionally, both N and GP38 antigens were integrated into a multiplex bead-based assay for simultaneous detection and applied to screen field samples from small ruminants in CCHFV endemic and non-endemic regions. Confirmatory tests such as virus neutralization tests and immunofluorescence assays were used to validate the results.

The multiplex assay demonstrated high suitability for screening of large sample sets, providing similar detection rates as compared to ELISA methods. This approach offers a robust tool for future studies and surveillance of orthonairovirus infections.

Speaker: Dr Caroline Bost (Friedrich-Loeffler-Institut, Institute of Novel and Emerging Infectious Diseases, Greifswald – Riems Island)

7:03 PM Small-scale spatial variability of mosquito abundance in an urban environment in Southern Germany

The incidence of mosquito-borne diseases is projected to rise across Europe in the context of climate change, as increasing temperatures, altered precipitation patterns, and changes in land use support the expansion of potential vector species. Urban climate adaptation measures like green spaces and water bodies may unintentionally affect mosquito distribution. Here we present findings of mosquito distribution in Augsburg, Southern Germany, and its rural surroundings to conduct a spatially differentiated risk assessment of potential vector occurrence along the urban-rural gradient. In 2024, mosquito trapping was conducted at 20 sites, expanded to 24 sites in 2025. At each trap location temperature and relative humidity are continuously measured. These data are supplemented by wind-measurements and satellite-derived information on vegetation and land use, as well as regional weather data to capture local climate conditions. Initial results show considerable small-scale differences in mosquito abundance between trap sites, even within the same urban area. By combining entomological data with environmental and spatial datasets, the study enables a differentiated risk assessment for mosquito occurrence. The findings contribute to a deeper understanding of urban mosquito ecology and inform targeted strategies for vector monitoring and control in European cities.

Speaker: Christian Voll (Regional Climate Change and Health, Faculty of Medicine, University of Augsburg)

7:04 PM Establishing methods to explore the role of olfactory epithelium in Borna disease virus 1 infection

Borna disease virus 1 (BoDV1) is a neurotropic virus that leads to a fatal non suppurative meningoencephalitis in humans and other dead-end hosts like sheep and horses and a persistent symptomless infection in its reservoir host, the bicolored white toothed shrew (Crocidura leucodon). The olfactory epithelium is an ideal entry point for neurotropic infections due to the direct connection of olfactory sensory neurons to the brain. In an animal experiment infecting shrews the olfactory epithelium cells are positive for BoDV1 in immunohistochemistry and in-situ hybridization. To study the role of the olfactory epithelium further under the aspect of 3R we are developing in-vitro methods to study infection. In the first step we are developing organotypic slice cultures and dissociated cell cultures with the rat olfactory epithelium to compare them with the olfactory epithelium of shrews. For the dissociated cell cultures, tissue from the nasal cavity is dissected and incubated with enzymes to dissociate. The cells are growing on poly-L-lysin coated glass coverslips in cell culture plates. The tissue for the organotypic slice cultures is grown on Millicell cell culture inserts. Slices are cut by hand or tissue chopper. The ongoing production of mucin from goblet cells and large pieces containing of cartilage, bone, connective tissue and neuronal provides challenges in adequate nutrition with cell culture medium. LDH-assays are used to asses cell damage.

Speaker: Elena Kloß (Justus-Liebig-Universität Gießen)

7:05 PM Development of an integrated genomic surveillance (IGS) of public health relevant pathogens in Germany for infectious disease control

IGS is an effective public health strategy for the surveillance of infectious pathogens. It combines whole-genome sequencing of notifiable pathogens and subsequent bioinformatics analyses with epidemiological case data from the reporting system and further laboratory analysis data.
One of the IGS's primary objectives is to rapidly identify significant pathogen dissemination and to ascertain infection links, even across disparate time periods and locations. Moreover, the IGS enables the continuous detection and monitoring of pathogen variants with evolving characteristics, such as transmissibility and virulence. In doing so, the IGS makes a significant contribution to the decision-making processes.
The RKI has implemented a strategy to build an internationally comparable IGS. Essential processes and infrastructure are being developed in collaboration with National Reference Centers, Consultant Laboratories, state laboratories, the University Medicine Network, and public health authorities.
Core activities include establishing harmonised sequencing workflows and deploying a high-performance bioinformatics and visualisation infrastructure that links sequence and case data in near real time, giving the possibility to also exchange information with other sectors. The knowledge gained from the IGS is passed on to various stakeholders, e.g. to the local health authorities as part of the reporting system, so that it can be used to adapt measures.

Speaker: Mrs Hanna Buck (Robert Koch Institute)

7:06 PM Mathematical Modeling of Breast Cancer Using Random Forest Model

This study presents a statistical and machine learning analysis of breast cancer data from 213 patients treated at the University of Calabar Teaching Hospital between January 2019 and August 2021. The dataset comprises key demographic and clinical variables, including age, menopause status, tumor size, invasive lymph nodes, metastasis, breast quadrant, personal/family history of breast disease, and diagnosis outcome (benign or malignant). The objective was to identify significant predictors of malignancy and evaluate the effectiveness of machine learning models in diagnostic classification.

Descriptive analysis showed a higher frequency of benign diagnoses (117) relative to malignant cases (90), with a peak age range of 45–55 years. Tumor size, lymph node involvement, and metastasis were highly right skewed, indicating that most patients presented with early stage characteristics. However, malignant tumors were typically larger and occurred in older women. Density plots and inferential tests (Chi-square, t-test, ANOVA) revealed statistically significant differences in age, tumor size, metastasis, and lymph node involvement between benign and malignant groups (p < 0.05). Menopause status was also significantly associated with tumor size, suggesting the influence of hormonal transitions in cancer development.

A Random Forest classifier was trained to predict malignancy based on the available features. The model achieved an accuracy exceeding 90% and a kappa statistic of 84.54%, reflecting high agreement and minimal classification bias. Feature importance analysis identified tumor size, invasive nodes, metastasis, and age as the top contributors to predictive performance. While variables such as breast quadrant, menopause status, and family history had lower influence, they provided complementary diagnostic information.

This study demonstrates that a combination of classical statistical methods and ensemble machine learning can provide actionable insights for early breast cancer detection and risk stratification. The findings reaffirm the clinical value of tumor size and lymph node status, and underscore the potential of data driven models to support diagnostic decisions. However, limitations include the presence of missing values and the dataset’s confinement to a single institution. Further work with larger, multicenter datasets is recommended to enhance generalizability and refine predictive accuracy.

The results contribute to the growing body of evidence supporting integrated statistical-machine learning frameworks in oncological research, with implications for screening, prognosis, and personalized care pathways.

Speaker: Ms Leona Diala (Margaret Lawrence University College of Medicine)

7:07 PM Seroprevalence of Coxiella burnetii (Q Fever) and the Impact of Farm Management Practices on Tick Infestation in Ruminants of Punjab, Pakistan

Ticks are recognized as potential vectors of Coxiella burnetii, a gram-negative, obligate intracellular bacterium and the causative agent of Q fever, a zoonotic disease affecting humans and a wide range of animals. This study aimed to assess the seroprevalence of Q fever in ruminants and the relationship between various farm management practices and the tick prevalence in livestock of four districts in Punjab, Pakistan. Thus, 96 farms were surveyed through structured questionnaires, each rearing cattle, buffaloes, goats, and sheep. Serum samples were collected from selected ruminants at each farm for detection of Coxiella burnetii antibodies. Further, ticks were screened by qPCR for C. burnetii and positive samples are currently undergoing further analysis through DNA sequencing. Overall, the Coxiella burnetii-seropositivity in ruminants was 12.10% (93/768). The seroprevalence varied between ruminant species, with 16.40% (63/384) in small ruminants and 7.55% (29/384) in large ruminants. The highest prevalence of anti- Coxiella burnetii antibodies (21.35%) was recorded for goats, followed by 11.97% for sheep, 9.37% for cattle and the lowest with 5.72% for buffaloes. The Q fever seropositivity was highest in Kasur with 7.29% (28/384) and followed by 7.03%, 6.51%, and 3.38% in Lahore, Bahawalpur, and Chakwal, respectively. All surveyed farms tested positive for coxiellosis. Similarly, high tick infestation was found in 85.4% of farms, with Bahawalpur showing a 100% infestation ratio. A logistic regression model identified farm bedding and the total number of animals as statistically significant risk factors for tick infestation at the farm. In this scenario, longitudinal studies are essential to understand the dynamics of tick infestation and the transmission of Coxiella burnetii in ruminants. Effective tick management practices may reduce the tick burden and mitigate the associated risk of zoonotic transmission of Q fever.

Speaker: Muhammad Husnain Ali Alvi (Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, 07743 Jena, Germany; Institute of Epidemiology, Friedrich-Loeffler-Institut, 17491 Insel Riems-Greifswald, Germany)

7:08 PM Towards One Health Institutionalization in Libya: leveraging stakeholders’ network for health system strengthening

Background: The identification and engagement of the key stakeholders is required to address One Health challenges.

Methods: Net-map tool was used to map and analyze the institutions linkage to assess their suitability to support One Health initialization in Libya.

Results: The key stakeholders were identified and categorized to build a strong collaboration to ensure a coordinated and effective approach to prevent, detect and response to health challenges. The consensus was reached and the actors were plotted on a stakeholder influence/interest matrix to visually represent their potential impact to the implementation of One Health. The network found that the NCDC and NCAH are heavily involved in network with number of connections followed by MoH, ESA, MoA, FDCC, MoE and MoLA. However, WHO ranked the highest among international organizations, while FAO and WOAH had a scored less influential toward the institutionalization. SWOT analysis was used to identify enablers and bottlenecks to the operationalization strategies.

Conclusion: The Key entities like NCAH, NCDC, MoH emerged as pivotal institutions in the network and crucial for overseeing the surveillance and control of zoonotic and vector-borne diseases in playing a leadership role in coordinating the One Health approach in Libya.

Speaker: Abdulaziz Zorgani (National Centre for Disease Control, Libya; University of Tripoli)

7:09 PM Molecular characterization of a novel mastadenovirus in harbor and grey seals

The rate at which novel mammalian adenoviruses have been discovered has rapidly increased in recent years. However, there is still limited information regarding the diversity of adenoviruses in marine mammals. In this study, we used pan-adenovirus family primers targeting the DNA polymerase to perform PCRs on tissue samples originating from harbor and grey seals that were found stranded or dead in 2020 and 2021 on the Dutch North Sea coast. This resulted in the amplification of specific adenovirus amplicons in tissues from ten harbor seals and one grey seal with Sanger sequencing and NCBI-BLAST analysis of the resulting sequences confirming the presence of two closely related strains of a novel mastadenovirus species. A PCR-based strategy using primers designed to bind to conserved regions of the genome has been utilized to enable characterization of the full genome sequence. Based on ICTV species demarcation criteria, the seal adenovirus is a candidate new adenovirus species. Phylogenetic analyses were performed using full-length sequences of the DNA polymerase, hexon, and penton genes and showed that the seal adenovirus was most closely related to polar bear adenovirus 1. These findings extend our knowledge of the diversity of viruses in European seal populations and highlight the necessity for additional studies to better understand the virological and host determinants influencing transmission of seal adenovirus among and between phocid species.

Speaker: Hannah Leah Elbo Morito (Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany)

7:10 PM MOZART: Model for Arbovirus Infection of the Skin

Mosquito-borne viruses such as Rift Valley fever virus (RVFV) and Chikungunya virus (CHIKV) cause significant global morbidity and mortality. Transmission via mosquito bite exacerbates disease severity, likely through immunomodulatory components of saliva. To facilitate mechanistic studies under physiologically relevant conditions and reduce reliance on animal models, we established a human skin explant system for mosquito-mediated arbovirus
infection.

In the pilot “MOZART” project, we optimized ex vivo human skin explant cultures and inoculated them either by Aedes aegypti probing or by microinjection. Quantitative RT-PCR analysis revealed that RVFV RNA copy numbers remained stable over a 7-day period, whereas CHIKV exhibited a modest but consistent increase. Immunohistochemistry of explants, together with infection assays in primary human dermal fibroblasts and keratinocytes, confirmed that both viruses productively infect skin cells.

Building on these results, we have developed a standardized protocol for presenting ex vivo Skin explants to infected mosquitoes. This platform enables precise dissection of early cutaneous host responses to natural arbovirus transmission and supports ethically responsible research into vector–host–pathogen interactions.

Speaker: Fanny Hellhammer (Research Group for Vector-Associated Biodiversity and Infections, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30559 Hannover, Germany; Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30559 Hannover, Germany. Actual address Gerold: Institute of Virology, Medical University of Innsbruck, Schöpfstraße 41, 6020 Innsbruck, Austria; Actual address Stegmann: Institute of Virology, Ulm University Medical Center, Albert-Einstein-Allee 11, 89081 Ulm, Germany)

7:11 PM Splicing regulatory elements in context of splice acceptor regulation in Influenza A

Pre-mRNA splice site selection and regulation critically depends on RNA-binding proteins, particularly members of SR and hnRNP families, which recognize splicing regulatory elements (SREs) near splice sites in a position-dependent manner. Of the Influenza A virus (IAV) segmented genome, segment 7 and 8 use the host splicing machinery to generate transcript variants through alternative splicing. Differences in SRE capacity and thus, splicing efficiency across subtypes may affect viral replication, gene expression and pathogenicity.
To investigate splicing regulation, in silico predictions of SREs near splice acceptors in segment 7 and 8 were performed using the HEXplorer tool. Splicing efficiency was assessed by qRT-PCR and Nanopore sequencing to detect minor variants. RNA affinity chromatography assays were used to identify subtype-specific RBPs near the splice sites in pre-pandemic, post-pandemic, and laboratory IAV strains.
Segment 8 exhibited clear subtype-specific differences: post-pandemic strains displayed an altered NS1/NS2 expression ratio. SRE profiles near the splice acceptor correlated with differential splicing. RNA affinity chromatography assays indicated altered SR protein recruitment across subtypes. Comparison with segment 7 revealed shared and distinct regulatory mechanisms. These findings emphasize strain-specific splicing regulation, suggesting adaptive control of gene expression that may inform future antiviral strategies targeting viral RNA processing.

Speaker: Caroline Meyer (Institute of Virology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany)

7:12 PM Unlocking Alimentary Transmission: How Milk Components Modulate Tick-Borne Encephalitis Virus Stability

Tick-borne encephalitis virus (TBEV) is not only transmitted by ticks but also via contaminated dairy products—a route that remains underappreciated despite its public health relevance. We explored how milk shapes viral survival in the digestive tract using simulated gastrointestinal conditions. Although milk can preserve TBEV infectivity at low temperatures, it acts very differently in the gastric environment, where it reduces viral stability and viability. This effect, driven by whey, casein, and lipids, suggests that rapid gastric transit is critical for successful infection. In the intestine, milk shields TBEV against bile salt–mediated inactivation, with casein emerging as the key protective factor. Thus, milk plays a dual role in TBEV alimentary transmission, limiting survival in the stomach but supporting persistence in the intestine. Our findings shed new light on how dietary components modulate viral stability, providing critical insights into the overlooked risk of foodborne tick-borne encephalitis.

Speaker: Michaela Berankova (Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 735, CZ-62500 Brno, Czechia; Laboratory of Emerging Viral Infections, Veterinary Research Institute, Hudcova 296, CZ-62100 Brno, Czechia; Laboratory of Arbovirology, Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branisovska 31, CZ-37005 Ceske Budejovice, Czechia)

7:13 PM Schmallenberg virus and bluetongue virus in biting midges: observations in the field

Schmallenberg virus (SBV) and bluetongue virus (BTV) are transmitted by Culicoides biting midges and affect ruminants. SBV was first found in Germany in 2011 and has today reached an enzootic status in central Europe. In 2006 BTV was introduced in central Europe and several serotypes has emerged ever since. In 2023 BTV-3 was detected for the first time in the Netherlands, rapidly spread to neighboring countries and caused a severe outbreak in Germany in 2024. The monitoring of viruses in the midges is of veterinary importance because the resulting diseases cause animal suffering and economic losses due to management and control measures.
To investigate the prevalence of the viruses in the vectors, altogether 810,237 biting midges were caught from 2019 to 2024 at 86 sites in Germany, grouped in 26,065 pools and were tested by PCRs for the genomes of SBV and BTV. SBV was detected every year in the biting midges and 4.9% of all pools were positive. While no BTV was found from 2019 to 2022, 0.02% of the pools were positive in 2023 and 7.4% in 2024, which corresponds to the reported BTV-3 cases in Germany. The most positive pools were sampled from August to October. No virus genome was found in the midges caught from December to March. The risk of virus transmission through biting midges seems to be elevated in summer and early autumn. Climate change with rising temperatures and mild winters could increase the risk of virus transmission in the spring and even the winter months.

Speaker: Sophie Zeiske (Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald – Insel Riems, Germany)

Tue, October 14

8:30 AM → 9:00 AM Registration

9:00 AM → 9:30 AM Keynote III: Amy Pruden: Informing and prioritizing AMR mitigation strategies through 'omics-based environmental surveillance

Convener: Szilvia Neuhaus

9:30 AM → 11:00 AM Session 6: Emerging Pathogens II

Conveners: Stephan Ludwig, André Schreiber

9:30 AM Comparative virology: Risk Group-4 viruses elicit divergent immune responses in the human endothelium

Andes virus (ANDV), Ebola virus (EBOV), and Nipah virus (NiV) are Risk Group-4 viruses that cause fatal zoonotic spillover in South America, Africa, and Asia, respectively. All three viruses cause severe vascular diseases, although they belong to distinct virus families. A major question in comparative virology is if different viruses have similar effects on the same cell-types they collectively target.
To address this, we innovated new approaches to generate nearly pure populations of artery or vein endothelial cells (ECs) from human pluripotent stem cells (hPSCs), a model that offers multiple advantages: they are genetically normal and more physiologically relevant than cancer cell lines prevalently used in research. Infecting hPSC-derived artery and vein ECs with ANDV, EBOV, and NiV revealed that these viruses elicit starkly different host effects. ANDV strongly induced interferon secretion, whereas EBOV and NiV did not. Therefore, while Risk Group-4 viruses are often assumed to block interferon production, ANDV remains an exception. Curiously, while EBOV did not induce interferon production, it strongly upregulated inflammatory cytokine IL-6. Therefore, EBOV appears to induce “immunological misfiring”, activating IL-6 while blocking interferon, thus decoupling these two arms of innate immunity.
This reveals starkly different effects of Risk Group-4 viruses on the human endothelium and highlight the utility of hPSC-derived vascular models to study high-risk pathogens.

Speaker: Dr Isabel von Creytz (Center for Biological Threats and Special Pathogens, Robert Koch Institute, 13343 Berlin, Germany)

9:45 AM A novel trans-Golgi-associated egress pathway of ORF3-deficient hepatitis E virus preserves quasi-envelopment in human hepatoma cells

Hepatitis E virus (HEV) normally exits host cells as quasi-enveloped particles by exploiting multivesicular bodies (MVBs), a process mediated by the accessory protein pORF3. To investigate the functional relevance of this pathway, an ORF3-deficient genotype 3c mutant (HEVΔORF3) was generated and analyzed in two human cell lines: hepatoma-derived PLC/PRF/5 and lung carcinoma-derived A549/D3 cells. While HEVΔORF3 reached wild-type levels of extracellular RNA in PLC/PRF/5 cells, it showed markedly impaired replication in A549/D3 cells, highlighting a strong cell-type dependency in the ability to compensate for the loss of pORF3. Despite reduced infectivity, virions from PLC/PRF/5 cells retained a quasi-envelope, as shown by gradient centrifugation, electron microscopy, and neutralization assays requiring detergent treatment. Confocal imaging revealed altered intracellular trafficking in HEVΔORF3-infected PLC/PRF/5 cells: pORF2 localization shifted from the MVB marker CD63 to the trans-Golgi marker TGN46. This switch was also reflected in virion composition, with TGN46 enriched in HEVΔORF3 particles. These findings identify an alternative, Golgi-associated egress route in hepatoma cells PLC/PRF/5 that preserves quasi-envelopment in the absence of pORF3. Given HEV's zoonotic potential and its ability to cross species barriers, identifying alternative release mechanisms is crucial for assessing host adaptation and transmission dynamics in the One Health context.

Speaker: Dr Nele Gremmel (University of Veterinary Medicine Hannover, Institute of Virology)

10:00 AM Risk assessment of Oropouche virus transmission by mosquitoes in Europe

Oropouche virus (OROV) has emerged as a significant health threat in Central and South America in 2024. Belonging to the genus Orthobunyavirus (family Peribunyaviridae), it is primarily transmitted by Culicoides midges; however, the role of mosquitoes in its transmission cycle has not been fully clarified. This study assesses the vector competence of five mosquito species (Culex torrentium, Cx. pipiens biotype pipiens, Aedes aegypti, Ae. japonicus, and Ae. albopictus) for OROV strain TR 9760 (isolated in 1955 from a febrile patient).
Performing infection via artificial bloodmeal and forced salivation assay under different temperature regimes and timepoints, no infection was detected in Ae. aegypti and Ae. japonicus, independent of timepoint or temperature regime tested. Interestingly, Cx. pipiens biotype pipiens and Cx. torrentium exhibited low-level susceptibility to OROV infection, but no virus was detected in their saliva, indicating they are unlikely to transmit OROV. In contrast, Ae. albopictus exhibited positive saliva, suggesting potential vector competence. Temperature-based risk analysis indicates that regions with established Ae. albopictus populations, may be at risk for OROV transmission.
These findings underscore the importance of virus surveillance and vector control in susceptible areas.

Speaker: Stephanie Jansen (BNITM/UHH)

10:15 AM Alphamesonivirus-1 in Culex pipiens: Genomic Insights and Diagnostic Tool Design

Mesoniviruses (Order: Nidovirales) are generally considered insect-specific viruses that do not infect vertebrates. However, this assumption was recently challenged by the detection of Alphamesonivirus-1 (AMV1) in two horses that died of acute respiratory syndrome in Italy (Jurisic et al.; J. Virol. 2025). Genetic analysis revealed a close relationship between the viral sequences isolated from the horses and those identified in local Culex mosquitoes, suggesting active local transmission. As part of metagenomic surveillance aimed at characterizing the virome of arthropod vectors, AMV1 RNA was detected in pools of Culex pipiens. These positive samples and the corresponding sequences were used to develop and validate a novel real-time RT-PCR assay for AMV1 detection, which was then compared to an existing pan-Mesonivirus qRT-PCR assay (Diagne et al.; Virus Res. 2020). The new assay was applied to hundreds of Culex mosquito pools collected across Italy to assess viral circulation. Additionally, AMV1 genomic variability was investigated. Three amino acid substitutions—located in ORF1a/ORF1b (RdRp), and ORF2a (Spike)—were uniquely identified in the horse-derived AMV1 sequence, potentially explaining the observed host switch. These findings underscore the importance of metagenomic surveillance in syndromic animals and highlight the need to monitor AMV1 circulation and evolution in Culex mosquito populations.

Speaker: Alessandra Spina (University of Teramo (UniTe), Teramo, Italy - Experimental Zooprophylactic Institute of Abruzzo and Molise (IZSAM), Teramo, Italy)

10:30 AM Multiplex serology to determine the role of wild boar as a reservoir host for hepatitis E virus and a sentinel host for West Nile virus and tick-borne encephalitis virus

Active wildlife surveillance, as part of a One Health approach, enables an early detection of emerging infections to allow the prevention of wildlife-human spillover events. The Eurasian wild boar (Sus scrofa) is a key wildlife species, which is widely distributed in Europe and easily adapts to different habitats. Wild boar and domestic pigs are the main reservoir for hepatitis E virus (HEV) genotype 3, which can be transmitted to humans mainly through consumption of undercooked meat. Wild boar can also serve as effective sentinels for emerging zoonotic pathogens like West Nile virus (WNV), a mosquito-borne orthoflavivirus, and the related tick-borne encephalitis virus (TBEV).
To establish an efficient multi-pathogen serological screening system for wild boar surveillance, we developed a multiplex Luminex magnetic bead-based assay for the detection of antibodies against HEV, WNV and TBEV. Screening of 960 wild boar sera collected in 2023 from eight districts in Saxony revealed high exposure levels to HEV and TBEV in wild boar, whereas WNV was detected at considerably lower levels. HEV RNA was found in five individuals, with phylogenetic analysis indicating a close relationship to subtype HEV-3i.
These findings provide evidence for the circulation of HEV, WNV and TBEV in Saxony, highlighting the value of multiplex serological screening in wild boar as an effective tool for wildlife-based surveillance of these viruses.

Speaker: Lydia Kasper (Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany)

10:45 AM Isolation of Chandipura virus from sandflies and detection of neutralizing antibodies in humans, Kenya

Chandipura virus (CHPV) is a sandfly-borne vesiculovirus, family Rhabdoviridae, causing outbreaks of febrile illness and severe neuroinvasive disease. Children can develop an acute encephalitis syndrome (AES) with a case fatality rate of 55-78%. Several outbreaks of CHPV have been reported in India. In 2024, India experienced a large outbreak with 245 cases of AES including 82 deaths. No human infections have been reported outside India, but CHPV has been found in a hedgehog from Nigeria and in sandflies from Senegal and recently from Kenya.
We isolated CHPV from sandflies collected in Kenya in 2019. The complete genomes of the two isolates showed 93-99% pairwise nucleotide identities to strains from Kenya, and 76-80% to those from India and West Africa. Comparative in-vitro phenotypic analyses of Kenyan, Indian, and Nigerian CHPV isolates in sandfly-, mosquito-, and human-derived cell lines, as well as in neuronal cells showed no impairment in genome replication rates and infectious virion production of the Kenyan isolate. Infection of mice with the Kenyan CHPV isolate resulted in rapid onset of neurologic disease and death with significantly higher viral loads in the brain than in other organs. CHPV neutralizing antibodies were detected in 19.4% (196/1.013) human sera collected from three counties in Kenya.
Our data provide evidence that CHPV is widespread in Kenya and infects humans. Testing for CHPV should be considered in patients with neuroinvasive disease in Kenya.

Speaker: Dr Inga Slothouwer (Institute of Virologie Charité Berlin)

9:40 AM → 11:10 AM Session 5: Environmental Pollution & Agriculture & Health

Conveners: Szilvia Neuhaus, Arne Hegemann

9:40 AM A rapid response mobile laboratory for (waste)water monitoring in emergency settings

Water monitoring represents a critical nexus in One Health frameworks, serving as the intersection where human, animal, and environmental health systems converge. Natural disasters frequently compromise water distribution networks and disrupt the laboratory infrastructure essential for water quality assessment. Here we present a portable laboratory utilizing commercially available testing platforms to deliver point-of-care water analysis capabilities. The system was deployed with the World Health Organization to a remote island near Madagascar, addressing critical water quality monitoring gaps following a post-cyclone emergency declaration.
The mobile laboratory incorporates a handheld device for comprehensive water analytics. The testing suite includes contamination indicator assays for alkalinity, free and total chlorine, phosphate, nitrate/nitrite, and ammonia, alongside rapid detection methods for manganese and arsenic. Microbiological assessment of E. coli and coliform bacteria is conducted through count plates and presence/absence tests. All analytical parameters operate within WHO standards. A rapid water concentration protocol enables efficient processing of surface water samples without requiring heavy laboratory equipment. The system features a mobile PCR component for detection of gastroenteric viruses and bacteria.
The demonstrable outcomes of this mobile laboratory deployment encompass enhanced emergency preparedness, inter-organizational collaboration, and operational adaptability. This integrated approach supports the maintenance of continuous water system surveillance, which is fundamental for preventing disease outbreaks, ensuring food security, and protecting vulnerable populations.

Speaker: Dr Arianna Ceruti (Institute of Animal Hygiene and Veterinary Public Health, Leipzig University)

9:55 AM The pESI plasmid may be a burden for Salmonella enterica serovar Infantis in plant environments

Plants serve very often as ecological niche for Salmonella enerica. Fresh plant foods consumed raw have been linked to numerous outbreaks. In recent years, one critical concern has been the multidrug resistance (MDR) observed in Salmonella strains. Among the many serovars, Salmonella serovar Infantis ranks as the fourth most commonly reported serovar in human infections. A megaplasmid named pESI (Plasmid of Emerging Salmonella Infantis) enhances Salmonella colonization in mammalian hosts and improves environmental fitness. It does so by carrying genes that confer resistance to various antibiotics. This megaplasmid is thought to contribute significantly to the successful spread of emerging S. Infantis strains. In our study, we used cress as a plant model for investigating Salmonella persistence. Two S. Infantis strains were included: one carrying the pESI megaplasmid and the other without it. Our results showed that the Infantis strain without pESI persisted better on cress. To explore this further, we obtained transconjugants by mating the two strains. These transconjugants were introduced separately onto cress. The findings confirmed that the strain without pESI exhibited better persistence, and the presence of pESI negatively impacted the strain’s ability to persist in the plant environment. The study revealed that, while pESI offers clear advantages for colonization in mammalian hosts, it acts as a burden for S. Infantis persistence in plant environments.

Speaker: Adam Schikora (Julius Kühn Institute (JKI))

10:10 AM The German Environmental Survey – 40 years of research on exposure to harmful pollutants in humans and their environment

The German Environmental Survey (GerES) is the largest study of human exposure to potentially harmful pollutants in Germany. Since the first cycle started in 1985, it has provided population-representative human biomonitoring (HBM) and ambient monitoring data for 40 years. The sixth cycle has just been completed, and recent samples of urine, blood, tap water, indoor and outdoor air, and house dust, alongside comprehensive questionnaire data (covering i.a. health status, living environment, dietary preferences, personal care product use, biocide application, environmental justice, climate change adaptation and sociodemographic information, among others), will again provide valuable insights into the environmental exposure of the German population. The combination of state-of-the-art analytical HBM methods, questionnaires and ambient monitoring allows for the identification of exposure sources and can also aid in quantifying exposure routes. This presentation introduces GerES as a prototype for a 'One and Planetary Health' survey that integrates human exposure and environmental pollution from various sources to facilitate effective policy advice on exposure reduction measures.

Speaker: Philipp Zimmermann (German Environment Agency, Berlin, Germany)

10:25 AM How soil health-promoting Streptomyces adapt to soil stresses

Actinobacteria of the genus Streptomyces play a crucial role in supporting a fertile and biologically active soil ecosystem due to their unique biological and ecological functions1. They secrete a broad array of hydrolases which break down complex organic compounds like cellulose and chitin needed for recycling of nutrients and enrichment of the soil. They also produce many different antibiotics that suppress soil-borne pathogens, promoting a healthier microbial balance. However, in their natural habitat soil, streptomycetes and other microorganisms are often exposed to rapid changes in their environment such as variations in osmolality due to rainfall or drought. How they adapt to different types of stresses they face in soil is not well understood.

Many strategies that bacteria evolved for the adaptation to stress involve complex second messenger signalling cascades2. Nucleotide-based second messengers are small, diffusible molecules which can be monomeric, such as 3´,5´-cyclic adenosine monophosphate (cAMP) or dimeric for example bis-(3´-5´)-cyclic dimeric adenosine monophosphate (c-di-AMP). Streptomyces use five different nucleotide-based second messengers for signal transduction with dedicated and to some extent overlapping functions3. c-di-AMP is produced out of two molecules of ATP by the deadenylate cyclase DisA and is hydrolysed to the linear pApA and further to AMP by the phosphodiesterase AtaC. Increased levels of the signalling molecule interfere with the formation of stress-resistant spores, while deletion of the deadenylate cyclase makes Streptomyces highly susceptible to osmotic stress4. The molecular mechanisms causing failures in cell functioning upon modulation of c-di-AMP are not yet fully understood. In our recent studies, we found that c-di-AMP affects a range of physiological functions at the cell-environment interface, such as transport and cell wall architecture, and thus fulfils a crucial role for stress adaptation in streptomycetes.

[1] Chater K.F., Biro S., Lee K.J., Palmer T., Schrempf H. The complex extracellular biology of Streptomyce. FEMS Microbiology Reviews, Volume 34, Issue 2, March 2010, Pages 171–198

[2] Bhowmick, S., Shenouda, M.L., and Tschowri, N. (2023). Osmotic stress responses and the biology of the second messenger c-di-AMP in Streptomyces. Microlife 4, uqad020

[3] Latoscha, A., Wörmann, M.E., and Tschowri, N. (2019). Nucleotide second messengers in Streptomyces. Microbiology 165, 1153-1165.

[4] Latoscha, A., Drexler, D.J., Al-Bassam, M.M., Bandera, A.M., Kaever, V., Findlay, K.C., Witte, G., and Tschowri, N. (2020). c-di-AMP hydrolysis by the phosphodiesterase AtaC promotes differentiation of multicellular bacteria. Proc Natl Acad Sci U S A 117, 7392-7400.

Speaker: Natalia Tschowri (Gottfried Wilhelm Leibniz Universität)

10:40 AM Environmental Burden of Disease of IQ loss attributable to lead exposure in Germany

Background: Lead is a pervasive environmental pollutant with no evidence for safe exposure levels in humans. Children represent a particularly vulnerable population due to higher absorption rates and their developing nervous system. Neurodevelopmental effects in children are the most sensitive health outcomes associated with lead exposure. This demonstrates the intricate connection between environmental and human health.
Methods: Environmental Burden of Disease (EBD) assessments enable the quantification of population health impacts attributable to environmental risk factors. We applied a probabilistic Monte Carlo simulation approach to EBD in order to comprehensively account for uncertainty across multiple input parameters. We used nationally representative human biomonitoring data from children and adolescents (3-17 years) in Germany to quantify neurodevelopmental effects from lead exposure.
Results: Our preliminary findings indicate ≈ 20.4 million IQ points lost (95% uncertainty interval [UI]: 12-28 million) attributable to lead exposure in German children. We estimated ≈ 85,000 (95% UI: 0 - 187,000) cases of mild intellectual disability (IQ <70) attributable to lead exposure. Further analyses to quantify Years Lived with Disability (YLDs) are currently ongoing.
Conclusion: Lead exposure in Germany remains a relevant public health concern. Our findings highlight the need for continued efforts to further reduce environmental lead concentrations and lead exposure of children.

Speaker: Paulina Sell (German Environment Agency, Exposure Assessment and Environmental Health Indicators, Berlin, Germany)

10:55 AM A holistic model to assess risk factors of fasciolosis in Ankole cattle

Contemporarily, remote sensing (RS) technology and geographical information systems (GIS) are increasingly used as tools for epidemiological studies and the control of zoonotic diseases. Fasciolosis, a zoonotic disease caused by a trematode parasite (Fasciola spp.), is a good candidate for the application of RS and GIS in epidemiology, strongly influenced by the habitat of the intermediate host. We examined variables which can increase the risk of fasciolosis in Ankole cattle, grazed in the degraded rangelands of north-eastern Rwanda. Risk variables considered included three environmental factors (normalized difference vegetation index, NDVI; normalized difference moisture index, NDMI; normalized difference water index, NDWI), two landscape metric variables (rangeland home-garden ratio, building density), two geological variables (percentage of poorly drained soil, elevation) and three husbandry variables (herd size, adult proportion, body condition score). Fasciola prevalence was used as the dependent variable, sampling season as a fixed factor and four principal components (condensed from the ten risk variables) as covariates in a univariate General Linear Model. Fasciola prevalence was positively correlated to rangeland proportion, cattle herd size, adult proportion and individual body condition. Moreover, high Fasciola prevalence was found in densely vegetated areas with high moisture (high NDVI and NDMI), in combination with large proportions of poorly drained soil at low elevations. Our study underlines the importance of ‘One Health’ and recommends a transdisciplinary approach for effective fasciolosis control integrating sustainable land management, enhanced livestock practices, and aims at public health interventions to mitigate the diseases’ impact on animals, humans, and the environment.

Speaker: Ping Sun (Leuphana University Lüneburg)

11:15 AM → 12:15 PM Poster Slam Viewing

11:15 AM → 12:30 PM Sideprogram: One Health Career Get-Together

Convener: Sascha Knauf

12:30 PM → 1:45 PM Lunch

1:45 PM → 3:15 PM Session 7: One Health in Public Health I

Conveners: Corinna Pietsch, Michaela Projahn

1:45 PM Geographic dispersal of West Nile and Usutu virus in Berlin, 2023-24

West Nile virus (WNV) and Usutu virus (USUV) are closely related arboviruses that circulate between birds and Culex mosquitoes. WNV infection can cause severe neurological disease while USUV is considered non-pathogenic in humans. This study examined the geographic dispersal and infection rates in mosquitoes of both viruses across Berlin.
Mosquitoes were collected across Berlin covering 50 sites in 2023 and 75 in 2024, and tested for WNV and USUV infection by RT-PCR. In total, 27,793 and 78,434 mosquitoes were collected in 2023 and 2024, respectively. For 2024, two-thirds of the samples have been analysed so far.
We observed a strong increase of virus-positive sites and dispersal of both viruses across the city. WNVsite-specific detection rates increased from 32% to 69% and for USUV from 42% to 87%. With respect to infection rates, a slight decrease was observed for WNV while those of USUV massively increased. WNV was detected in 105 mosquito pools (3.1 %, minimum infection rate (MIR) = 3.78) in 2023 and in 147 pools (2.6%, MIR = 2.94) in 2024. USUV was found in 84 mosquito pools (2.5%, MIR = 3.0) in 2023 and in 247 pools (43.7%, MIR = 4.94) in 2024. Genome sequencing of detected strains is ongoing to investigate if viruses emerged from local amplification or were introduced, and to analyze their phylogeographic spread.
Our study provides evidence for the extensive circulation and ongoing distribution of WNV and USUV in Berlin. Public awareness campaigns should be considered.

Speaker: Dr Corinna Patzina-Mehling (Charité - Universitätsmedizin Berlin)

2:00 PM More than the Sum of Its Parts: Combining Genomic and Epidemiological Data for Comprehensive and Sustainable Pathogen Surveillance

Interconnecting multiple fields and methods has become a crucial part of surveillance systems throughout the recent decade. In this work, we developed a system to integrate data from Germany's mandatory notifications for infections with genomic data in a continuous manner. This constant flow of integrated data enables new insights into the dynamics of and serves as a benchmark for detecting logistical, technological, and scientific challenges of Germany’s surveillance system.
One crucial aspect represents the automation of processes by setting up new digital solutions and standards. The data integration requires a primary ID for sample identification, as well as a secure ID used exclusively for linking case and genomic data. A generic set of properties describes the biological sample and its journey to genomic sequencing. This metadata is utilized, among others, to assess turnaround time and identify potential improvements to expedite the process from sampling to the initialization of public health measures.
In conclusion, the digital developments and infrastructure in this work facilitate the integration of patient-related information with pathogen properties, providing the base for scalable and comprehensive surveillance. The patient's symptoms during their sickness, along with existing risk factors and mutations in the pathogen’s genome, allow us to detect correlations that serve as a basis for testing causation and identifying new areas for public health measures.

Speaker: Felix Hartkopf (Robert Koch-Institut)

2:15 PM A customized, lightweight mobile laboratory vehicle for outbreak investigations with highly dangerous pathogens - experiences from a field trial in Germany

In an EU Horizon program funded project, a prototype of a mobile laboratory was developed, combining proven mobile units with advanced high-security laboratory architecture in a optimized space. This innovative, game-changing laboratory can be easily transported to remote outbreak areas, and swiftly set up as a fully functional diagnostic laboratory for processing human, veterinary, and environmental samples.
The laboratory is equipped with a central safety area. This zone is sealed from the external environment by a HEPA-filtered, negative pressure system, ensuring the safe and secure handling of highly pathogenic agents, such as risk group 3 (e.g. West Nile virus) and risk group 4 pathogens (e.g. Crimean-Congo hemorrhagic fever virus). Beyond its first-class safety features, the laboratory is an example of forward-thinking sustainability. Equipped with cutting-edge photovoltaic systems, it operates with ultra-modern, energy self-sufficiency, underlining a strong commitment to environmental responsibility and green energy solutions. To assess its operational readiness of the mobile laboratory, a field trial was conducted in Germany, which included collecting and analyzing bird feces samples for the presence of avian influenza (proof of concept study). For this purpose, detection methods for AI were successfully established within the mobile unit, and samples were analyzed and the results communicated to the responsible authorities.

Speaker: Markus Keller

2:30 PM NGS-based genomic surveillance of West Nile virus in a One Health framework

West Nile virus (WNV) circulates primarily in an enzootic transmission cycle between Culex mosquitoes and birds, with mammals serving as accidental hosts. Humans infections can be asymptomatic or lead to flu-like symptoms, severe neurological disease and even death. WNV has been found almost worldwide, with the number of infections in humans and animals in Germany increasing over the last seven years. In addition to WNV hotspot areas such as Berlin, the virus spread also to other major cities such as Leipzig, Hamburg and Dresden. In the study presented here, we analysed the whole genomes of 86 WNV isolates from diseased birds collected in 2023 and 2024 by a nationwide bird surveillance network coordinated by the FLI. The sequencing results were assessed phylogenetically and -geographically. All WNV strains detected in 2023-2024 belonged to known lineage 2 clusters, with no evidence of new introductions. Most bird cases were linked to subcluster 2.5.3.4.3c. Phylogenetic analysis dates the most recent common ancestor to mid-2018, supporting a single introduction followed by local endemic spread. A few sequences clustered in subcluster 2.5.3.2, indicating additional independent introductions. The detection of novel mutations in certain samples raises the possibility of viral adaptation to local hosts or changes in transmission dynamics, underscoring the need for continued genomic surveillance and epidemiological monitoring as part of a One Health approach.

Speaker: Ms Anne Schwarzer (Friedrich-Loeffler-Institut)

2:45 PM Assessment of Toxic Heavy Metals in Soil, Vegetables and Grasses Irrigated with Healthcare Wastewater and Associated Health Risks in the Akaki River Catchment, Central Ethiopia

Healthcare facilities generate wastewater that contain a variety of potentially toxic heavy metals, including lead (Pb), cadmium (Cd), chromium (Cr), and zinc (Zn), which are often discharged into nearby rivers. This study investigates the concentration of heavy metals in healthcare wastewater (HCWW) released into the Akaki River Catchment (ARC) and assesses its potential health and environmental impacts in central Ethiopia. Samples of HCWW, soil, selected vegetables, and grasses were collected from discharge points and adjacent irrigation areas. Tap and wastewater samples were analyzed for physicochemical properties and heavy metal content, while soil, vegetables, and grass samples were analyzed specifically for heavy metals using photometry and the Agilent 5800 ICP-OES instrument. The estimated daily intake (EDI) of heavy metals was calculated based on their concentrations in vegetables and the typical consumption rates of those vegetables and grasses. Except temperature, all the measured physicochemical parameters were surpassed recommended maximum limits (RML). In vegetable samples, the mean concentrations of Cd, Cr, and Pb (ranging from 1.82-4.23, 0.03-7.22, and 1.78-26 ppm, respectively) exceeded the RML established by the joint WHO/FAO guidelines. Lettuce and tomato exhibited the highest levels of Pb and Cd, while salad, carrot and beetroots were notably contaminated with Zn and Cr. In soil samples, the mean concentrations of Pb (34.13-35.36 ppm), Zn (7.66-8.6 ppm), and Cd (3.25-4.23 ppm) also exceeded FAO's RML. Likewise, in irrigated wastewater samples, the mean concentrations of Cr (3.71ppm), Cd (2.68ppm), and Pb (0.04ppm) surpassed the limits set by the US EPA guidelines. Grasses from irrigated areas also contained Pb, Cd, Cr, and Zn of 13.53, 2.16, 0.03 and 5.47 ppm concentrations respectively with Pb, Cd and Zn being above the recommended limits. The EDI, transfer health index (THI), and hazard index (HI) calculated for vegetables and grasses consumed by humans and livestock indicated elevated exposure, particularly for Pb, Cd, and Zn. In conclusion, the discharge of healthcare wastewater has compromised the suitability of river water for urban agriculture, livestock drinking, and the safe consumption of vegetables and animal products grown in wastewater-irrigated areas. Improving river water quality is crucial to mitigate potential health risks and to ensure the sustainable use of water resources.

Speaker: Dr Jirata Shiferaw Abosse (Addis Ababa University, College of Veterinary Medicine and Agriculture)

3:00 PM Genomic Characterization of Highly Pathogenic H5N1 Avian Influenza Viruses in Wild and Domestic Animals in Argentina Using a One Health Approach

In 2022, HPAI H5N1 clade 2.3.4.4b (B3.2 genotype) reached South America, causing poultry outbreaks, mass die-offs in marine mammals, and a severe human case in Chile, highlighting its zoonotic potential.
Through collaborative efforts between virologists, ecologists, and public/veterinary health agencies, full-genome sequences of H5N1 viruses in Argentina were generated and we identified two distinct B3.2 introductions. The first, in Feb 2023, via wild birds in the northwest, spreading southward and mainly affecting poultry (limited wildlife spillover). The second, in Aug 2023, entered via marine mammals in southern Argentina, spread north along the Atlantic coast, and caused mass mortality in elephant seals and sea lions.
We showed that viruses from this second wave belong to a distinct “marine mammal” subclade, carrying mammalian-adaptive mutations (PB2-Q591K, D701N) that may enhance transmission among them. We further identified that these viruses diversified into two sublineages with different geographic patterns and retained the ability to infect seabirds, indicating an expanding host range.
In Feb 2025, after nearly a year without outbreaks, we detected a novel triple reassortant H5N1 virus in backyard poultry. Our phylogenetic analysis revealed the first reassortment between H5N1 B3.2 and South American low pathogenicity avian influenza viruses, underscoring the need for continued surveillance and genome sequencing to monitor zoonotic HPAI H5N1 evolution in the region.

Speaker: Agustina Rimondi (Robert Koch-Intitut)

1:45 PM → 3:15 PM Session 8: Genomics & Proteomics

Conveners: Torsten Semmler, Sébastien Calvignac-Spencer

1:45 PM Evolutionary Dynamics of Bluetongue virus Strains Circulating in Italy, 2024-2025

In 2024, Italy experienced a major resurgence of Bluetongue (BT), a viral disease of ruminants caused by Bluetongue virus (BTV), an RNA virus circulating in multiple serotypes transmitted by Culicoides midges. By April 2025, over 7,000 confirmed cases had been reported, mainly involving serotypes BTV-3, BTV-4, and BTV-8. We performed whole-genome sequencing (WGS) and phylogenetic analyses on BTV strains collected across multiple Italian regions in 2024. Among the BTV-3 strains, we identified at least three distinct genomic constellations: two resulting from multiple reassortment events with other European strains, and one closely related to Northern European BTV-3. BTV-4 strains also displayed diverse genomic profiles, with individual gene segments of varied origin. BTV-8 showed up to 100% nucleotide identity in segment 2 with strains from France, suggesting likely spread via trade of viremic animals. Moreover, BTV-8 genome segments were found within both BTV-3 and BTV-4 strains, highlighting the role of reassortment in shapingBTV evolution. These findings reveal the complex genomic landscape of BTV in Italy and emphasize the value of WGS for monitoring viral dynamics.

Speaker: Gloria Plebani (Università degli Studi di Teramo, Istituto Zooprofilattico Sperimentale Abruzzo Molise-Teramo)

2:00 PM Nanopore-Based Methylome Profiling of Microbial Communities

The methylome, defined as the complete set of genome-wide methylation marks, provides an additional layer of information beyond the genetic sequence, yet remains largely underexplored in bacterial genomics. Recent advances in Nanopore sequencing now allow investigation of DNA methylation not only in isolates but also at the community level, opening new opportunities to study epigenetic variation in complex microbiomes and better understand microbial ecology and adaptation.
We are analyzing the metagenome and the metamethylome of seal microbiomes using Nanopore sequencing, as part of a project investigating antimicrobial resistance (AMR) acquisition on those sentinel species. By applying state-of-the-art ONT basecalling tools combined with in-house pipelines, we examine how DNA methylation varies across species and strains. A complementary study investigates Klebsiella pneumoniae isolates from wastewater, providing insights into how methylation patterns differ between environmental populations and those from host-associated communities.
Beyond biological insights, we aim to integrate methylation data into metagenomic workflows. We assess how methylation can improve early-stage classification by filtering out eukaryotic sequences and enhancing binning accuracy, especially in linking mobile genetic elements like plasmids to host genomes. These efforts contribute to a deeper understanding of epigenetic mechanisms in AMR and support a broader One Health approach connecting environmental, animal, and human health.

Speaker: Valentina Galeone (RKI)

2:15 PM Combining Short- and Long-Read Sequencing to Investigate a Ralstonia pickettii Outbreak Linked to Contaminated Saline Solutions

In December 2023, the WHO reported a Ralstonia pickettii outbreak in Australia linked to contaminated saline solutions. Concurrently, German surveillance detected an increase in nosocomial R. pickettii bacteremia cases, prompting a national outbreak investigation.

From August 2023 to June 2024, 15 patient isolates were sequenced using Illumina whole genome sequencing. Five of these were additionally sequenced using Oxford Nanopore Technology (ONT). Combining short- and long-read data enabled the reconstruction of complete genomes. Similarities to publicly available data were assessed with core genome multilocus sequence typing (cgMLST), using a newly created scheme.

Six isolates from patients in three hospitals across different federal states clustered within ≤6 allele differences. German and Australian outbreak clusters differed by at least 43 alleles, requiring further investigation into their potential link.

Rapid genomic investigation enabled cluster identification and assessment of relatedness to the other outbreaks, supporting epidemiological investigation. The absence of a standardized cgMLST scheme, limited public data, and sparse documentation of analyses in prior studies posed key challenges. Although, ONT allowed the recovery of complete genomes and plasmids, its increased error rates inflated cgMLST distances, highlighting the usefulness of combined long- and short-read data for bacterial outbreak investigations.

Speaker: Dr Vladimir Bajić (Genome Competence Centre (MF 1), Robert Koch Institute, Berlin, Germany)

2:30 PM Multi-omics investigation of L-sorbose metabolism in high-risk Escherichia coli lineages linking fitness and virulence

Certain sequence types (STs) of Escherichia coli, such as ST131 and ST648, belong to high-risk clonal lineages that pose serious public health threats by combining antimicrobial resistance (AMR), fitness, and virulence. In contrast, other subtypes e.g., ST10 are typically harmless and beneficial colonizers. To identify characteristics beyond AMR, we analyzed over 22,000 E. coli genomes and discovered the L-sorbose (sor) phosphotransferase system (PTS) as a marker enriched in high-risk lineages but nearly absent in commensals. Multi-omics analyses revealed sor-dependent induction of the sor PTS and activation of associated pathways including motility, capsule biosynthesis, and purine and tryptophan metabolism. Functional validation via knockout mutants confirmed a fitness advantage linked to the sor-operon. Notably, introducing the operon into a commensal strain increased virulence in the Galleria mellonella model. The widespread presence and induction of the sor-PTS in high-risk clones highlight its potential role in linking metabolism, fitness, and virulence. Further studies, including in vivo models, are planned to elucidate its potential as a pathogen-specific target for alternative therapies. Such targeted strategies may reduce antimicrobial use and thereby resistance selection, supporting One Health goals by limiting AMR emergence and spread across human, animal, and environmental sectors.

Speaker: Lena-Sophie Swiatek

3:00 PM Automatic sequential clustering in the context of integrated genomic surveillance

Integrated Genomic Surveillance (IGS) enables the surveillance of various, public health-relevant bacterial and viral pathogens. For bacterial species, the identification of genomic clusters represents the foundation for outbreak investigations and epidemiological studies. Providing well-defined genomic clusters therefore represents an essential task of IGS, in order to support the surveillance of relevant bacterial species by the federal and local health authorities in Germany.

For the automatic computation and definition of genomic clusters, a diverse set of challenges has been identified: the dependence on external data silos should be minimized, the clustering and its nomenclature should be robust over time and the clusters should represent meaningful groupings, even in the presence of samples with lower quality (e.g. missing data).

Within this work, these challenges are addressed and advantages as well as disadvantages of some possible solutions are highlighted and discussed. Finally, the current analytical approach and the software implementation utilized within the IGS project, termed Seqsi (SEQuential SIngle-linkage clustering), is presented.

Speaker: Torsten Houwaart (Genome Competence Centre (MF1), Robert Koch Institute, Berlin, Germany)

3:15 PM → 3:45 PM Keynote IV: Andrea Winkler: 10 recommendations for a better life: The Lancet One health Commission Report.

Convener: Sébastien Calvignac-Spencer

3:45 PM → 5:15 PM Scientific Speed Dating

Convener: Sascha Knauf

5:15 PM → 6:00 PM Coffee & Poster Viewing II

5:15 PM Non Toxic Antibacterial Activities of Depsidones from Timorese Endophytic Fungus Corynespora cassiicola against Methicilin and Multidrug-Resistant Bacteria

Chemical investigation of the screened active extract from fungal endophyte Corynespora cassicola associated with medicinal plants Anonna squamosa collected in Timor Island (Indonesia) led to the isolation of four depsidone compounds corynesidone A (1), B (2), C (3) and D (4). The individual compound was tested for their antibacterial property against multi drug resistant bacteria and for their cytotoxic activity against murine lymphoma (L5178Y) cell line. While compound 1-4 were inactive in the cytotoxic assay, they displayed antibacterial potency toward multi drug resistant clinical isolates Staphylococcus aureus 25697 (MRSA) with MIC value of 16-64 μg/mL. Moreover, compound 3 was found to be active against Streptococcus pneumonia with MIC value of 32 μg/mL.

Speaker: Maxs U.E Sanam (Department of Veterinary Science, Nusa Cendana University, Jalan Adisucipto Penfui, 85001 Kupang, Indonesia)

5:16 PM Novel Production Methods of Kojic Acid from a Novel, Non-Toxicogenic strain of Timorese Strain Aspergillus Flavus

Prolonged exposure to sunlight can harm human skin, causing issues like sunburn, skin cancer, and oxidative stress. To counteract these effects, kojic acid is used in cosmetics like creams and lotions because it can inhibit hyperpigmentation. Kojic acid is also used in the food industry to prevent browning. Due to its wide range of uses in cosmetics, food, and pharmaceuticals, among other fields, there is a high demand for kojic acid. Kojic acid is typically produced by certain fungi, specifically Aspergillus flavus and Aspergillus oryzae. A major concern is that these fungi can also produce other toxic compounds, such as aflatoxins and cyclopiazonic acid, alongside kojic acid. Research has shown that various Aspergillus species produce a mixture of these compounds. For example, strains of A. flavus from Argentinean peanuts were
found to produce kojic acid, aspergillic acid, cyclopiazonic acid, and aflatoxins. Similarly, other Aspergillus species have been shown to produce both kojic acid and aflatoxins. In this study we report the production of kojic acid from non-toxicogenic strain of Timorese Strain Aspergillus Flavus which produce only kojic acid without the co-production of harmful aflatoxins and cyclopiazonic acid. Solid state fermentation using rice and traditionally ground corn combined with the application of small quantity of suitable solvents leading to production high purity of kojic acid crystals. The high purity of kojic acid crystals has been known to play significant role in the stability of cosmetics products and other products. Solid state fermentation using rice/corn media combined with the suitable (cheaper) solvent for extraction and crystallization revealed the most efficient and cheapest production of kojic acid compared to the more labor work and cost using sub merged fermentation.

Speaker: Antonius R. B. Ola (Department of Chemistry, Faculty of Science and Engineering, Nusa Cendana University, Jl. Adisucipto Penfui, 85001 Kupang, Indonesia; Integrated Research Center (Bioscience) Laboratory, Nusa Cendana University, Jalan Adisucipto Penfui, 85001 Kupang, Indonesia)

5:17 PM Divergent Genotype of Hepatitis A Virus in Alpacas, Bolivia, 2019

Hepatitis A virus (HAV) is a common human pathogen causing acute hepatitis. Human HAV belongs to species Hepatovirus A, genus Hepatovirus, family Picornaviridae. HAV strains of Hepatovirus A are only found in humans (genotypes I-III) and monkeys (genotypes IV-VI), with no non-primate reservoir host. We screened serum and faeces of 70 alpacas and llamas from Bolivia for novel viruses using undirected Illumina High Throughput Sequencing, and detected a divergent HAV. In a PCR screen of 64 alpacas and 6 llamas, we detected HAV RNA in serum and/or faeces of ~9% of alpacas, but not in llamas. In ELISA analysis, we found HAV antibodies in ~64% of alpacas and ~67% of llamas, suggesting HAV infection is common. Complete-genome analysis of alpaca HAV suggests that it is a novel non-primate genotype of Hepatovirus A. Phylogenetic analysis indicates a long association of HAV with alpacas. HAV in alpacas is similar to human HAV infection: RNA is present in serum and faeces at viral loads comparable to human infection, and immunity builds up over life. Alpaca HAV might belong to the same serotype as genotypes I–VI. Consequently, HAV vaccinations, especially for camelid handlers, should be considered to reduce spillover risk.

Speaker: Talitha Veith (Institute of Virology, Charité - Universitätsmedizin)

5:18 PM Comparative analysis of immune responses in human and Egyptian Rousette bats upon Cedar virus infection

Multiple fruit bat species within the genus Pteropus have been confirmed as reservoir hosts for Henipaviruses, e.g. Nipah virus (NiV), Hendra virus (HeV) and Cedar virus (CedV). Nevertheless, numerous henipaviruses and henipavirus-like viruses are identified in many other bat species worldwide, including Egyptian Rousette bats (Rousettus aegyptiacus, ERB), supporting the possible roles of ERB in Henipavirus transmission into livestock and humans. Thus, investigating henipaviral infection in ERB is of great importance to uncover its potential spillover of henipaviruses. As a novel Henipavirus, CedV shares significant similarities with the highly virulent NiV and HeV, while it does not induce any disease in various animal challenge models. It is well-established that human ephrin A2, A5, B1 and B2 are able to mediate the entry of CedV. However, whether ERB cells can support its entry and replication remains unclear. To answer this question, we generated pseudoviruses and the recombinant fluorescent CedV and performed high content microscopy imaging and flow cytometry assays. Our results suggested that ERB ephrin B1 and B2 mainly mediated CedV entry into ERB cells. Further, CedV replication was observed in ERB cells, as well as in human cells. Intriguingly, CedV infection induced a delayed interferon (IFN) expression in ERB cells, indicating IFN antagonism by CedV in ERB cells. Future research will investigate the inhibitory mechanisms in different hosts by CedV.

Speaker: Gang Pei (Friedrich-Loeffler-Institut)

5:20 PM Bioaerosol occurrence and transmission of antimicrobial resistances in pig husbandry

Dust can contain microorganisms that are both pathogenic and resistant to antimicrobials (AMR), which can potentially transmit airborne infectious and zoonotic diseases. Agriculture is one of the largest producers of primary particle matter, accounting for approximately 20% of global fine dust emissions. The tenacity of aerosolised pathogens depends on the characteristics of the particles, such as size and mass density, and the resilience of the pathogens to environmental factors. Aerosols from and inside animal barns are being investigated as a potential source of airborne pathogens. While it is known that the use of antibiotics in agriculture often results in antibiotic-resistant bacteria, the extent to which environmental factors can alter the bacterial composition of bioaerosols, and the associated risks to humans and the environment, remain open research questions. In AirBarn, the size and density of fine dust particles in pig barns will be measured. The prevalence of pathogenic microorganisms on airborne particles and the occurrence of antibiotic resistance will be investigated. Assuming that the abundance of AMR bacteria in bioaerosols varies depending on environmental conditions (temperature and humidity), we will use microscopy, bacterial cultivation, next generation sequencing and PCR/qPCR analysis to analyse bioaerosols, in particular the abundance of ESKAPE bacteria, in the pig barns. The aim is to improve our understanding of the aerobiology of pathogen-containing aerosols on pig farms.

Speaker: Mrs Marie Wiedenhöft (1,2)

5:22 PM CD8+ T Cells in Urine are a Distinguishing Marker in Schistosomiasis

Introduction
Schistosomiasis (Bilharzia) is a Neglected Tropical Disease caused by trematode parasites, with Schistosoma haematobium being a primary cause of urogenital Schistosomiasis in sub-Saharan Africa (SSA). After a prepatent period, paired adult worms produce eggs in the venous plexus of the bladder, which are shed in urine from infected humans. However, some eggs become trapped in host tissues, leading to granuloma formation and inflammation in urinary tract and renal damage.
Rationale
We aim to identify biomarkers in urine and blood which indicate disease progression as other easily assessable morbidity markers are not established.
Hypothesis/Methods
The underlying hypothesis is: Disease progression correlates with increased levels of immune cells, Tubular Epithelial Cells (TECs), and antibodies in urine or blood, which are expected to decline following effective treatment.
Here, we are going to investigate total counts of immune cells and TECs in urine via flow cytometry as well as hematological and biochemistry markers in blood samples in negative controls (n=20), recently infected returning travelers (RT) (n=22), and S. haematobium-infected (n= 9) and uninfected participants (n= 4) from an endemic region (EP).
Results
Our preliminary results revealed that CD8⁺ T cells in urine were exclusively detected in the EP group, especially in S. haematobium-infected EP (median: 96; IQR: 40-286.5), while they were nearly absent in negative controls (0.5; 0-2.8), recently infected RT (0; 0-2), and uninfected EP participants (3.5; 0-424).
Conclusion
This finding shows that CD8+ T cells in urine are a distinguishing biomarker between recently infected RT and EP participants.

Speaker: Meral Esen (Universitätsklinikum Tübingen, Institut für Tropenmedizin, Reisemedizin und Humanparasitologie (ITM), Abt. VII – Medizinische Fakultät, Wilhelmstr. 27, 72074 Tübingen, Germany; Centre de Recherches Médicales de Lambaréné (CERMEL), Fondation Internationale de l´Hôpital Albert Schweitzer, B.P: 242 Lambaréné, Gabun, Africa; Deutsches Zentrum für Infektionsforschung (DZIF), Partner Site Tübingen, Germany; Universität Tübingen, Cluster of Excellence (EXC) 2124: Controlling Microbes to Fight Infection, Germany)

5:23 PM Class switch toward IgG2 and IgG4 is more pronounced in BNT162b2 compared to mRNA-1273 COVID-19 vaccinees

Objectives:
Vaccination against SARS-CoV-2 induces antibodies that reduce the risk of severe disease. Because IgG subclasses differ in their ability to activate complement, to bind Fc receptors and neutralize viruses, it is crucial to understand how IgG subclass responses differ between vaccine platforms.

Design:
IgG1, IgG2, IgG3, and IgG4 binding antibodies against SARS-CoV-2 trimeric spike protein, receptor-binding domain, and S1/S2 subunits responses were quantified using a multiplex immunoassay, after a booster dose of either BNT162b2 (Pfizer/BioNTech) or mRNA-1273 (Moderna) in a healthy cohort (n = 165) who had received two previous vaccine doses.

Results:
Boosting increased all subclass IgG levels, except for S1-specific IgG1 and S2-specific IgG2. However, IgG2 and IgG4 levels were significantly higher in BNT162b2 than in mRNA-1273 vaccinees (P = 0.0313 [IgG2 S] and P = 0.0106 [IgG4 RBD], P = 0.0070 [IgG4 S1]). Individuals who had previously received a non-mRNA vaccination showed no significant increase in IgG2 (P = 0.4909 [S]) and IgG4 (P = 0.0607 [S]) post-boost.

Conclusions:
Vaccine-specific differences post-booster vaccination were identified and may drive the class switch between IgG2 and IgG4 responses. Given their different roles, these subtle differences may ultimately also affect long-term immunity and protection.

Speaker: Alex S. Siebner (Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany; German Center for Infection Research, Partner Site Tübingen, Germany)

5:24 PM Investigation of the influence of antimicrobial peptides on the developmental stages of Toxoplasma gondii

Toxoplasma gondii is an intracellular protozoan parasite of high medical relevance, especially in immunocompromised individuals and during pregnancy. Current therapeutic approaches are limited in their efficacy across the parasite’s life cycle stages and often associated with adverse effects. Antimicrobial peptides (AMPs), particularly cationic (KAMPs) and proline-rich peptides (PrAMPs), have emerged as promising candidates for adjunct antiparasitic therapies due to their broad-spectrum activity and low cytotoxicity.

This study aims to investigate the morphological and ultrastructural effects of selected AMPs on T. gondii in vitro. Special attention will be given to their action on both tachyzoites and bradyzoites, the latter being notoriously resistant to conventional treatment. Using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and scanning transmission electron microscopy (STEM), we seek to characterize AMP-induced alterations on parasite membranes, intracellular organelles, and host-parasite interfaces. Beyond its descriptive anatomical scope, this project contributes to a mechanistic understanding of AMP action at the cellular level and to evaluate their potential as a supplement to existing therapeutic strategies. Establishing the morphological correlates of AMP activity could serve as a basis for the development of targeted interventions against toxoplasmosis and other apicomplexan infections.

Based on preliminary in vitro models, we hypothesize that AMPs exposure may result in disturbed ribosome assembly and membrane disruption in T. gondii, potentially impairing essential cellular processes such as protein biosynthesis and intracellular survival. These assumptions will be systematically tested through morphometric and ultrastructural analyses.

Initial results indicate lower survival rates of the tachyzoites as determined by DAPI staining.

Speaker: Ms Pauline Tonndorf-Martini (Leipzig University, Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, An den Tierkliniken 43, 04103 Leipzig, Germany.)

5:25 PM Governance of the fight against antimicrobial resistance according to the “One Health” approach in Senegal between 2023 and 2024.

Introduction
In response to public health emergencies such as epidemics and pandemics, Senegal established the High National Council for Health Security (HCNSS) in 2017, at the Prime Minister's Office. The high council ensures the coordination, implementation, monitoring and evaluation of the national multi-sectoral health security program based on the “One Health” approach. Among the various bodies working within the HCNSS, the multisectoral technical working group on Antimicrobial Resistance (AMR-TWG) is one key component, tasked with the coordination of national actions taken to combat antimicrobial resistance.
The aim of this study is to assess the implementation of strategic activities in the fight against AMR. Specifically, it evaluates the achievements of the AMR-TWG and identifies its constituent members.
Methodology
A comprehensive review and synthesis of the various reports produced from different activities of the AMR-TWG was carried out. Additional data were collected through participant observation and documentations of activities.
Results
The AMR-TWG includes over 60 national stakeholders, including 31 ministerial departments and agencies, 12 universities and research institutes, professional organizations, the private sector, civil society and community platforms. Between 2023 and 2024, the group held 15 meetings and workshops. As a result, the first AMR national action plan (AMR NAP) was reviewed, monitored and evaluated. The data analysis from the latter was used as a reference base to develop the second AMR NAP (2024 – 2028) that the RAM TWG revised, monitored and evaluated the implementation of the first RAM National Action Plan (RAM NAP) 2017-2022.
The development of the second AMR NAP (2024-2028) was completed in collaboration with various institutions such as the Directorate of Laboratories, Directorate of Veterinary Services, and public and private laboratories across human, animal, environmental, and food health sectors and technical and financial partners implementing Global health security. The new AMR NAP 2024-2028 was validated by the AMR-TWG, and approved by the HCNSS “One Health” steering committee.
The group also developed a national strategic communication plan for social and behavioral change against antimicrobial resistance, and coordinates the celebration of the World Week Against Antimicrobial Resistance through training sessions, community awareness campaigns, scientific conferences and events, etc.
Conclusion
The cross-sectoral, multidisciplinary approach of the AMR-TWG has strengthened national governance and positioned the HCNSS as an opinion leader in the global fight against antimicrobial resistance. However, it is necessary to decentralize AMR initiatives in the context of the territorialization of public policies and promote AMR data sharing among stakeholders.

Speaker: Dr Khadija Sandembou Diop (Haut Conseil National de la sécurité sanitaire "One Health")

5:26 PM Fine dust in focus: effects on molecular mechanisms during respiratory infections

Air pollution poses a severe global health problem, contributing to over seven million deaths annually. Fine particulate matter (PM), primarily from fossil fuels, industry, and traffic, is associated with respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), and lung cancer, while also impairing innate immunity and increasing susceptibility to infections.
Influenza A viruses (IAV) cause severe respiratory infections, often accompanied by bacterial or fungal coinfections. Airborne spores of Aspergillus spp. can lead to invasive pulmonary aspergillosis (IPA) or influenza virus-associated aspergillosis (IAPA) in immunocompromised individuals. Although PM exposure has been linked to aggravated respiratory infections, the molecular mechanisms remain poorly understood.
This study expands in vitro cell culture models and an ex vivo mouse-lung system to investigate PM's direct effects on pathogen-host interactions. Viral load will be assessed via plaque assays, while hyphal growth will be analyzed using immunofluorescence microscopy. To elucidate PM-induced molecular effects, planned techniques include Western blot, flow cytometry, immunofluorescence microscopy, qRT-PCR, and transcriptomics.
Preliminary experiments suggest that PM modulates the IAV-induced innate immune response in THP-1 macrophages. We will provide initial insights into PM-mediated effects on pathogen burden, cellular homeostasis, and innate immunity.

Speaker: Dr Sarah König (Section of Experimental Virology, Institute of Medical Microbiology, Jena University Hospital)

5:27 PM Innovative Barn Design and Decontamination Strategies for Open Barn Systems in Swine and Poultry Husbandry

The ongoing threat of zoonotic pandemics, exemplified by outbreaks of avian influenza, for example in Europe and North America, underscores the persistent risk of future pandemics originating from animal husbandry.
In order to mitigate pathogen transmission in and out of animal husbandry, numerous biosecurity measures are implemented on farms. However, with an increasing consumer demand for more animal welfare, open systems become more important. These systems, characterized by fresh air and outdoor access, facilitate greater environmental exchange, potentially increasing the risk of pathogen entry and dissemination, particularly for airborne viruses. In addition, some biosecurity measures are less effective or more difficult to implement in open housing systems.
Within the framework of the Leibniz Lab Pandemic Preparedness, we therefore focus on possible prevention strategies for pathogen spread in open swine and poultry housing. In a first step, we analyze existing innovative barn design options enhancing biosecurity, e.g., options that allow easier cleaning, animal isolation and the prevention of wildlife contacts. Additionally, we focus on novel decontamination methods suitable also for outdoor areas.
Subsequently, recommendations for suitable structural and decontamination measures, based on costs, effectiveness and effort, will be given to assist policymakers, stakeholders, and farmers in selecting optimal biosecurity strategies to prevent the transmission of potentially pandemic pathogens in open husbandry systems.

Speaker: Dr Corinna Thomas (Leibniz-Institut für Agrartechnik und Bioökonomie e.V.)

5:28 PM Sonar: A High-Performance Multi-Pathogen Genomic Surveillance System

The COVID-19 pandemic highlighted the critical importance of functional genomic surveillance and rapid outbreak detection. Here, we present Sonar, an open-source, high-performance tool for multi-pathogen genomic surveillance capable of computing, storing and efficiently querying genomic mutations and metadata of millions of samples. The tool consists of the following three main components: a) an intuitive and interactive web application enabling any user to explore genomic data, track pathogen dissemination, and analyze sample characteristics; b) a robust backend architecture designed for systematic storage, annotation, and retrieval of mutations and customizable metadata, scalable to diverse pathogens; c) a versatile command line interface for genomic analysis tasks such as sequence alignment, variant calling, annotation and advanced querying, that integrates seamlessly into subsequent bioinformatics workflows. Sonar has been successfully deployed and validated at the Robert Koch Institute, Germany’s public health institution, and applied to various viruses, including SARS-CoV-2, RSV, HIV, Influenza, Ebola, and Dengue. The generic design of Sonar facilitates immediate processing of emerging pathogens, significantly reducing response times. Its flexible structure supports future extension to other zoonotic and environmental pathogens, aligning with the One Health approach to enhance global pandemic preparedness and informed public health decision-making processes.

Speaker: Yusra Seyam (Genome Competence Center (MF1), Robert Koch Institute)

5:29 PM Impacts Land Use and Climate Change on the Spread of Antibiotic Resistance in Agricultural Soils

Livestock manure is a primary source of antibiotic resistance in agricultural soils, with land-use type and climatic factors significantly influencing the levels and distribution of antibiotic resistance genes (ARGs). However, the combined effects of climate change and shifts in land use on the spread of antibiotic resistance from livestock manure to soil microbiomes remain largely unexplored. Within the One Health Platform, the ResistChange project addresses this knowledge gap using the Global Change Experimental Facility, which investigates the consequences of climate change on ecosystem processes across different land-use types. In this study, soils representing various agricultural management practices are amended with manure and incubated under both current and future climate scenarios based on IPCC projections. The soil resistome is analyzed via metagenomics, and the abundance of key resistance genes is quantified over time using qPCR. Preliminary results indicate that maximum water holding capacity (WHC) plays a significant role in ARG dynamics, as current soils retain more water than those projected under future climate scenarios. Metagenomic analysis of the manure revealed a predominance of vancomycin- and tetracycline-related ARGs. Our findings suggest that soil variables such as WHC, climate scenarios, and management practices influence the spread of ARGs in soil. Understanding these factors will enhance our ability to protect the health of humans, animals, and ecosystems in line with the One Health approach.

Speaker: Luis Daniel Prada Salcedo (Helmholtz Cente for Environmental Research - UFZ)

5:30 PM AMR monitoring in wastewater: detection and characterization of carbapenemase-producing Klebsiella pneumoniae

Infectious diseases caused by multidrug-resistant pathogens represent a growing global public health threat, leading to millions of deaths each year. In 2024, the revised European urban wastewater treatment directive was adopted, mandating the surveillance of antimicrobial resistance (AMR) in wastewater. The AMELAG project aims to develop reliable detection methods to monitor influent wastewater. Due to its clinical relevance, carbapenemase-producing Klebsiella pneumoniae (CPKP) were selected as initial screening target for the proof-of-concept study. A filtration-based method was employed, involving colony enumeration on selective media, species verification and susceptibility testing, followed by PCR screening for key resistance genes and whole genome sequencing (WGS) of selected isolates. CPKP counts ranged between 102-104 colony-forming units (cfu)/100 ml. Overall, 326 subcultures were obtained, with 297 K. pneumoniae (93 %) including 253 (79 %) CPKP. PCR screening identified blaOXA-48 as the most common carbapenemase gene across the isolate collection, followed by blaNDM-1, blaKPC, and blaVIM. WGS revealed a broad range of sequence types among CPKP isolates, i.e. ST15, ST35, ST37, ST147, ST258, ST273, ST307, and ST485. Overall, the combination of culture-based methods and molecular analysis demonstrates a promising framework for monitoring and characterizing AMR in influent wastewater.

Speaker: Katharina Werner

5:31 PM COX-SAVE: Development of a Coxiella burnetii Secure Advanced Vaccine based on E-beam technology

Q fever is caused by Coxiella burnetii (Cb), a zoonotic pathogen mainly shed by ruminants during abortion or parturition. Human infection can occur through inhalation of contaminated aerosols. Although a commercial vaccine exists for ruminants, it can induce adverse reactions and does not fully prevent bacterial shedding, highlighting the need for a more effective and safer vaccine. The COX-SAVE consortium is developing a Nine Mile phase II (NMII) Cb vaccine candidate based on a novel inactivation method, - low-energy electron irradiation (LEEI) - which inactivates pathogens by damaging nucleic acids while preserving structural antigens like proteins and lipopolysaccharide, which are essential for eliciting protective immunity. LEEI enables precise control of irradiation dose, ensuring complete inactivation while maintaining antigenic integrity. Compared to conventional chemical inactivation, LEEI offers enhanced reproducibility and rapid processing, without the need to remove chemicals post-inactivation. Based on qPCR, vacuole formation and immunofluorescence staining, application of 25 kilogray (kGy) was determined as inactivation dose. The in vitro characterization of the pathogenicity and immunogenicity of the vaccine candidate is carried out via cell culture-based assays in L929 cells and in primary macrophage cultures. Initial immunization studies will be conducted in sheep, followed by trials in cattle to assess the protective efficacy of the Cb-LEEI vaccine.

Speaker: Dr Gustavo R. Makert (Fraunhofer-Institut for Cell Therapy and Immunology)

5:32 PM Biocide susceptibility in Staphylococcus aureus CC1 and CC1660

Human (n=64) and equine (n=29) Staphylococcus aureus isolates of the clonal complexes 1 and 1660 were investigated for their phenotypic biocide susceptibility, biocide resistance genes and efflux capacity. Broth microdilution was performed for benzalkonium chloride (BAC), octenidine, polyhexanide and chlorhexidine. Whole genome sequences were screened for qac genes, which were confirmed by PCR in 26 isolates. Increased efflux activity was determined by evaluating fluorescence emitted by ethidium bromide accumulated in the cells. For this, cartwheel assays were performed for the qac positive isolates and one qac negative control. Real time fluorometry was performed for eight isolates. Two control strains were included in both assays. Biocide susceptibility testing revealed unimodal distributions. For BAC, minimum inhibitory concentrations (MICs) of 1.25-5µg/mL were detected. Of the 24 isolates with a BAC MIC of 5 19 carried qacA, four qacC and one qacC S99L. Two of the 19 isolates with a MIC of 2.5 were qacC positive. The cartwheel assays showed increased efflux activity in 18 qacA and all seven qacC positive isolates. Real time fluorometry confirmed this for the selected isolates. Within the qacC positive isolates, the isolate carrying the qacC mutation S99L showed lower efflux activity for both methods. To investigate the effect of the efflux activity on the isolates’ BAC susceptibility, susceptibility testing with efflux inhibitors will be performed.

Speaker: Ms Johanna Jahnen (Institute of Microbiology and Epizootics, Centre for Infection Medicine, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany; Veterinary Centre for Resistance Research (TZR), Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany)

5:33 PM A Caenorhabditis elegans life-dead-assay for the estimation of the pathogenic potential of Shiga toxin-producing Escherichia coli from food samples

Shiga toxin-producing Escherichia coli (STEC) are important food-borne pathogens. The severity of clinical symptoms can vary from diarrhea to haemolytic-uremic syndrome and death. In STEC, the Shiga toxin subtype and the occurrence of additional virulence factors have an impact on the clinical manifestation. STEC from food can vary in serotype and virulence associated genes (VAGs) from those usually connected to severe clinical cases. Therefore, an assessment of the pathogenic potential of food isolates for humans would be helpful. Here, we established a Caenorhabditis (C.) elegans life-dead-assay to estimate the pathogenic potential of STEC from food samples. Five STEC strains harbouring different Shiga toxin genes and respective stx deletion mutants were tested concerning their impact on the lifespan of C. elegans SS104. For the life-dead-assay, worms were synchronized to the same L4 larval stadium. Fifteen worms were seeded on fresh nematode growth medium plates with either the non-pathogenic E. coli OP50 control strain or a challenge strain. Numbers of life and dead worms were counted each day. Kaplan-Meier survival curves were calculated using R and the median survival times (MSTs) of three technical and biological replicates were determined. For all tested strains, MSTs of the worm populations were reduced compared to the control strain OP50 but varied in the extend of the reduction. Worms fed on OP50 had an MST of 11 to 12 days. MSTs for STEC strains harbouring the stx2i variant were reduced to 8 to 11 days, respectively. STEC strains harbouring a stx2g variant led to a further reduction of the MST to 6 days. Deletion of the stx2g gene led to an increase of the MST compared to the wild type strain to 6.5 days. A C. elegans life-dead-assay for in vivo pathogenicity determination experiments for STEC from food samples was successfully established. Reductions in the MSTs for STEC were determined but vary according to the Shiga toxin subtype and the occurrence of further VAGs. The shape of the Kaplan-Meier survival curves differed between STEC strains and the investigated deletion mutants, respectively. Therefore, further detailed analyses could improve the discriminatory power of the Caenorhabditis elegans life-dead-assay.

Speaker: Michaela Projahn

5:34 PM Hands-On Science at Greifswald Zoo: CiFly 2.0

The citizen science project CiFly, now in its second year, demonstrates how young students can actively participate in scientific investigations. In 2025, CiFly engages ninth- and tenth-grade students alongside researchers to study biodiversity and the prevalence of antimicrobial resistance (AMR) in and around Greifswald Zoo. After being introduced to One Health, biodiversity, microbiology, molecular biology, and scientific working procedures, students began their first fieldwork in April. Each week for five weeks, five groups of students collected samples along transects from 20 locations, with five additional locations sampled by scientists. In total, 18 flies, 30 water samples, and approximately 75 leaf swabs were collected, and students recorded observations of around 160 animals. Bacterial cultures were prepared from the flies and water samples, while DNA was extracted from leaf swabs. This DNA was then amplified both in the school and in laboratories to enrich and ultimately sequence mammalian and bird DNA. With the resulting data, students will be able to explore and answer their own research questions.

Speaker: Johanna Eberhard (Helmholtz Institute for One Health)

5:35 PM Distinct responses to Marburg and Sudan viruses in Egyptian rousette bat macrophages reveal co-adapted immunological features

Egyptian rousette bats (ERBs) are natural reservoirs of Marburg virus (MARV, family Filoviridae) – etiologic agent of viral hemorrhagic fever with high mortality rates in humans and non-human primates. Recent studies have sought to better understand the immune-related features that grant bats the ability to asymptomatically harbor zoonotic viruses. To elucidate mechanisms of MARV co-adaptation in ERBs, we generated bone marrow-derived macrophages (bmMs) and compared their responses to MARV and Sudan virus (SUDV), a related filovirus not harbored by these bats. Infection with SUDV resulted in higher intracellular viral RNA levels than MARV. Viral progeny in cell supernatants decreased over time for SUDV, but not MARV-infected cells, highlighting differential viral replication. Transcriptional gene expression analysis demonstrated clear differences in filovirus-induced responses. SUDV induced the differential expression of significantly more genes than MARV, including various Type I and III interferons, cytokines and chemokines, contrasting a muted response to MARV. Pathogen-induced signaling pathway analysis indicated differential regulation of downstream immune responses to MARV and SUDV. We show for the first time that ERB innate immune cells experience differential viral replication and display clear pathogen-specific responses to two distinct filoviruses, corroborating growing evidence of highly specific one virus-one bat coevolutionary relationships.

Speaker: Ivet Yordanova (Robert Koch Institute)

5:36 PM Resistome analysis of German hunted wildlife animals by capture hybridization enrichment

Wildlife may act as vehicle for the transfer of AMR bacteria at the human-livestock-wildlife interface. By analyzing resistomes in fecal samples from hunted animals, we aimed to investigate the occurrence of AMR genes in different animal species in order to assess possible transmission pathways.
Fecal swabs were collected directly in the field from hunted animals in Brandenburg and the Harz region. Samples were enriched in buffered peptone water. Cultures from the same animal species were pooled prior to DNA extraction. Sequencing libraries were used to enrich AMR genes by bait-based hybridization capture enrichment followed by NGS with a depth of 162.5 Mbp per sample.
In the season 2024/25, we investigated 73 pooled samples (wild boar n=31; roe deer n=24; red deer n=14; fallow deer n=4) from 284 animals of 21 driven hunts for the presence of AMR genes. Resistance genes were detected in all samples. In total, AMR genes against 16 antimicrobial classes were found. Wild boar had the highest number of resistance genes per sample, with genes for up to 15 antimicrobial classes detected. 42 samples harbored ESBL/AmpC genes, with the most abundant gene families being blaACC (n=19), blaCMY (n=18), blaACT (n=12) and blaDHA (n=10). Five samples harbored carbapenemase encoding resistance genes belonging to the blaOXA, cphA- or cfiA-families. CTX-M, the most abundant ESBL family in livestock and humans, was not detected, indicating a limited anthropogenic impact on the observed patterns.

Speaker: Dr Alexandra Irrgang (German Federal Institute for Risk Assessment)

5:37 PM Comparative Analysis of Metagenomic and Isolate Sequencing: A Case Study targeting carbapenemase-producing Klebsiella pneumoniae in influent wastewater in Germany

Metagenomic sequencing captures abundant DNA of a samples, enabling cultivation-free analysis of microbial communities. Wastewater (WW) metagenomics offers a powerful tool for monitoring pathogen spread and antimicrobial resistance genes (ARG) that may threaten public health. Here, we compared metagenomic data with cultured isolate sequences of Klebsiella pneumoniae (KP), a major healthcare-associated pathogen according to the WHO.

Twelve metagenomes from two WW treatment plants in Germany were sequenced with Illumina and 56 cultured KP isolates from the same samples with Illumina and ONT. Hybrid assemblies enabled high-quality genome reconstruction from isolates which were compared to metagenomes by applying modern tools for ARG screening.

Genomic analysis of the isolates revealed multiple sequence types and resistance patterns. Even though ONT data allowed for more contiguous assemblies they missed several small plasmids and ARGs, indicating that a combined approach might be beneficial for full genomic analysis. Metagenomes yielded few KP reads, insufficient for genome recovery. Around 50% of metagenomic reads were unclassifiable, reflecting dataset complexity. Cultivation-based sequencing was essential for detailed genomic profiling, while metagenomics provided broader community and resistome insights, including resident environmental species.

This study highlights the complementary strengths and limitations of each approach for pathogen and ARG monitoring in WW.

Speaker: Dr Daniel Desirò (Robert Koch-Institut)

5:39 PM Knowledge and use of antibiotics by community members in the Asante Akim North District, Ghana: a mixed-methods approach

Background. Antimicrobial resistance (AMR) is a pressing One Health challenge. This study employed a mixed-methods approach to assess antibiotic knowledge and use among community members in the Asante Akim North District, Ghana.
Methods. Using a mixed methods design, we triangulated findings from anthropological and socio-epidemiological approaches. A cross-sectional survey was conducted with 1,114 participants, complemented by 11 semi-structured interviews. In addition, participant observation was carried out over one year in a semi-rural town and one month in a rural village, alongside free discussions and semi-structured interviews. Data were analysed respectively using STATA 17 and NVivo 14. Quantitative and qualitative results were merged at analysis level.
Results. Most community members knew the term antibiotics (61.7%) and showed substantial knowledge. We observed low antibiotic use (2.3%) during the four weeks before data collection with varied usage modes. Community members used antibiotics based on local knowledge and practical reasoning shaped by lived experience. Few had heard of AMR (34%), and none reported direct experience. The lack of knowledge on AMR suggests it is not a lived reality.
Conclusion. Substantial existing knowledge on antibiotics among community members was observed and should be considered for the development of AMR interventions. Future studies should explore other factors related to AMR beyond individual responsibility of community members.

Speaker: Maresa Neuerer (Heidelberg Institute of Global Health)

5:40 PM Assessing willingness to vaccinate against Lyme borreliosis among adults in Germany

Introduction
Lyme borreliosis (LB) is the most common tick-borne disease in Europe. Considering its high incidence in Europe and increasing epidemiology, it is critical to understand drivers of vaccination intention and what influences them among adults in Germany.

Methods
We used an existing survey panel to conduct an online survey in 2022 of adults aged 18-65 years old in 20 European countries, with recruitment quotas on age, gender, and region. The survey included questions about knowledge of LB, tick exposure, and willingness to vaccinate against LB. We conducted descriptive analyses with weighting.

Results
Of 2732 respondents, 96% were aware of ticks and 85% were aware of LB. Among those aware of both, 74% reported they would be likely or very likely to get vaccinated against LB if their healthcare provider (HCP) recommended it, and 77% would be likely or very likely to get it if free of cost and recommended by their HCP. Furthermore, 58% would get vaccinated even if they had to receive multiple doses.The main barrier for vaccination was concern about possible vaccine side effects (51%). Most respondents believed that vaccination would decrease their chances of getting sick with LB (75%) and would reduce the likelihood of severe disease (77%).

Conclusion
In Germany, adults were generally likely to get vaccinated against LB. Side effects of the vaccine were a barrier to vaccination, but respondents believed vaccination would reduce their chances of getting sick with LB. Effective communication of LB risk and vaccine safety by HCPs may further increase willingness to vaccinate against LB among adults.

Speaker: Dr Claudius Malerczyk (Pfizer Pharma GmbH)

5:41 PM Learning One Health: A Student-Led Exploration of Interdisciplinary Collaboration through the Lens of Bat Health

The One Health approach emphasizes the interconnectedness of human, animal, and environmental health—necessitating collaboration across diverse disciplines. Young professionals must not only develop expertise in a specific field but also learn early on how to work effectively in interdisciplinary teams while developing a common understanding of concepts, definitions, approaches and boundaries of their respective disciplines.

This student-led project on bats—an ecologically vital and taxonomically diverse order of mammals facing conservation challenges while being recognized as reservoirs for multiple zoonotic pathogens—brings together participants from veterinary medicine, human medicine, biology, and educational science. Beginning with foundational insights into One Health, students explore their disciplinary perspectives and the unique contributions each field offers. Through guided collaboration, the group maps the One Health domains related to bat health to (i) identify key aspects of interdisciplinarity (e.g. discourses, actors, networks, forms of knowledge) and (ii) co-develop a survey tool for qualitative research with representatives from various disciplines, with the objective to collect key factors that contribute to successful interdisciplinary collaboration—including boundary work, translation between disciplines, tools for decision-making, and team dynamics.

This project aims to explore the understanding of interdisciplinary collaboration while contributing to early interdisciplinary experiences, and will support future professionals in learning how to address One Health challenges.

Speaker: A.L. Arnecke (Universität Leipzig)

5:43 PM Disrupted Soil Microbiomes from Fusarium Infections Threaten Reproductive Success in an Endangered Turtle Species: A One Health Perspective

Fungal pathogens pose an emerging threat across ecosystems, yet their role in One Health contexts remains underexplored. Fusarium spp., listed by WHO as high-priority fungal pathogens, affect plants, animals, and humans. In this study, we examined the impact of Fusarium infections on microbial communities in the nests of the endangered European pond turtle (Emys orbicularis) in Austria’s Donau-Auen National Park. Across 238 environmental and biological samples, we found that Fusarium presence in nest soil significantly reduced bacterial richness and phylogenetic diversity—microbial shifts that were directly associated with lower hatching success. Interestingly, fungal community composition remained stable, highlighting bacteria-specific disruptions. These results suggest that Fusarium may destabilize key microbiomes that underpin soil and host health. Our findings demonstrate how soil serves as a critical interface in One Health systems—linking environmental integrity to wildlife reproduction and disease risk. Integrating microbiome monitoring into conservation efforts may offer novel insights into mitigating emerging infectious disease risks in wildlife conservation contexts.

Speaker: Magdalena Meyer

5:44 PM Learning from COVID-19: Implementation Perspectives from Users and Rejectors of SARS-CoV-2 Mail-in Tests to Inform Future Testing Strategies

Despite the important role of testing as a measure against the COVID-19 pandemic, user perspectives on SARS-CoV-2 tests remain scarce, inhibiting an improvement of testing approaches and pandemic preparedness. Conducted amid the second pandemic wave (late 2020 – early 2021) during a multi-arm trial evaluating SARS-CoV-2 surveillance strategies in Baden-Württemberg, Germany, this qualitative sub-study aimed to gain a deeper understanding of how test users and rejectors perceived mail-in SARS-CoV-2 gargle tests. We conducted 67 semi-structured in-depth interviews via telephone or video call. Interviews were audio-recorded, transcribed verbatim and analyzed inductively using thematic analysis. Respondents generally described gargle sampling as simple and comfortable. However, individual perceptions of the testing method and its feasibility varied widely. Self-sampling was appreciated for lowering infection risks during testing but also considered more complex. Gargle-sampling increased participants’ self-efficacy. Communication and trust decisively influenced the intervention’s acceptability. User-driven insights on how to streamline testing include: consider communication, first impressions of tests and information as key for successful mail-in testing; pay attention to the role of mutual trust between those taking and administering tests; implement gargle self-sampling as a pleasant alternative to swab testing; offer multiple test methods to increase test up-take.

Speaker: Freda Röhr (Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany)

6:00 PM → 7:30 PM Members Assembly & Election SAB

8:00 PM → 10:30 PM Conference Dinner

10:30 PM → 11:59 PM Party (aka "Music, Table Tennis & Drinks")

Wed, October 15

8:30 AM → 9:00 AM Registration

9:00 AM → 9:30 AM Keynote V: Mirjam Jenny: Health communication and human health behavior in times of climate change

Convener: Fabian Leendertz

9:30 AM → 11:00 AM Session 9: One Health in Public Health II

Conveners: Michaela Projahn, Katharina Schaufler

9:30 AM From Field to Genome: Genomic characterization of pneumococcal strains circulating at the human-wildlife interface in Sub-Saharan Africa

Lower respiratory tract infections are among the leading causes of death for children under five in Sub-Saharan Africa, with Streptococcus pneumoniae being the most common causative agent. Beyond its public health impact, S. pneumoniae has been shown to have implications for the conservation of endangered species, as humans have inadvertently transmitted the bacteria to wild great apes resulting in lethal outbreaks. Understanding serotype diversity and antimicrobial resistances at a local scale can guide tailored public health interventions, such as the selection of appropriate vaccines and antibiotic treatment, which can reduce disease burden and the risk of transmission to wildlife.

We conducted genomic characterization of pneumococcal strains carried asymptomatically by humans living and working in proximity to great apes in Taï National Park, Côte d’Ivoire, and Dzanga-Sangha Protected Areas, Central African Republic. A total of 473 nasopharyngeal swabs were collected; from these, 43 S. pneumoniae strains were isolated directly in the field using a solar-powered incubator. Molecular and genomic analyses were performed at the Institut Pasteur de Bangui, Centre Hospitalier Universitaire de Bouaké and the Helmholtz Institute for One Health in Greifswald. We revealed the circulation of multiple serotypes, including both vaccine-covered and non-covered types, and the presence of distinct antimicrobial resistance patterns. This study highlights how genomic surveillance can provide relevant data to inform prevention and treatment policies within a One Health framework.

Speaker: Moritz J.S. Jochum (Helmholtz Institute for One Health)

9:45 AM Anthrax outbreak associated with handling and consuming meat from animals that died suddenly, Kanungu District, Uganda, June–November 2024

Background: Anthrax is a recurrent zoonotic threat in Uganda, with eleven outbreaks reported in 2024. On September 17, 2024, the Ministry of Health confirmed two human anthrax deaths in Kanungu District–the first recorded outbreak in the district. We investigated to determine the scope, identify risk factors, and recommend evidence-based control measures.
Methods: We defined a suspected cutaneous anthrax case as skin lesions (papule, vesicle, or eschar) with ≥2 of skin itching, reddening, lymphadenopathy, fever, or malaise. Suspected gastrointestinal anthrax was abdominal pain with ≥2 of vomiting, diarrhea, fever, or loss of appetite in Kanungu residents (June 1–November 4). Confirmation required PCR detection of Bacillus anthracis. In a 1:2 unmatched case-control study, we enrolled all cases and asymptomatic neighbors from the two most affected sub-counties. Logistic regression identified risk factors.
Results: We identified 90 cases (86 suspected and 4 confirmed); 80% cutaneous, 11% gastrointestinal, 9% both. Males were more affected (AR=48/100,000) than females (AR=15/100,000). The case fatality rate was 6.7%. Bugongi (AR=257/100,000) and Katete (AR=224/100,000) were most affected. Risk factors included consuming meat from suddenly dead animals (aOR=5.8, 95% CI: 2.7–12.0), handling their carcasses (aOR=9.3, 95% CI: 2.5–15.0), and lower education (aOR=6.2, 95% CI: 2.5–15.0). Most cases bought meat from one butcher sourcing such animals.
Conclusion: The outbreak was linked to consuming and handling meat from animals that died suddenly. We recommend mandatory pre-slaughter inspections, safe carcass disposal, and targeted community education.

Speaker: Charity Mutesi (Uganda National Institute of Public Health)

10:00 AM Evaluating response to an anthrax outbreak using 7-1-7 metrics in Southwestern Uganda, September 2024

Background
Uganda has responded to 37 anthrax outbreaks in the past decade. In 2021, the country adopted the 7-1-7 framework which stipulates outbreak detection in 7 days, notification in 1 day and completion of early response actions in 7 days. Kanungu District at the border with Democratic Republic of Congo (DRC) reported its first known anthrax outbreak on September 17, 2024. We assessed response to this outbreak using the 7-1-7 approach.

Methods
We used the 7-1-7 metrics to document the dates of emergence, detection, notification, and completion of early response actions. We held discussions with the district leadership, health workers, and community members to establish key dates and facts, and to identify bottlenecks and enablers. Qualitative data were organized into themes to capture bottlenecks and enablers.

Results
The disease emerged in animals on June 15, 2024 and was detected after 85 days. In humans, the time from emergence (June 26, 2024) to detection was 77 days. The district One Health Team was notified 1 day after detection. Early response actions were jointly initiated after 5 days and completed in 13 days for human health, and in 14 days for animal health. Overall, the outbreak involved 111 sudden animal deaths, and 90 human anthrax cases with 6 (6.7%) human deaths. Enablers for immediate notification included presence of a real-time One Health communication platform for health workers. Bottlenecks included weak zoonotic disease surveillance characterized by understaffing, low suspicion index for anthrax, and weak coordination with private health facilities.

Conclusion
The response to Kanungu District’s first documented anthrax outbreak met only one (notification) of the 7-1-7 timeliness targets, facilitated by an existing real-time One Health communication platform. This study reveals missed opportunities for early detection and response, posing potential cross-border health risks. The findings underscore the need to adopt the 7-1-7 framework within Uganda’s animal health sector and to strengthen One Health coordination, event-based surveillance, and frontline veterinary capacity in high-risk areas

Speaker: Charity Mutesi (Uganda National Institute of Public Health)

10:15 AM One Health in Austria: What agencies can do to implement international recommendations at national level

Inter-agency collaboration involves cooperation and/or coordination between two or more institutions or within components of the same institution. This collaboration can be defined as any joint activity that achieves a greater public benefit than if the institution were to act alone. Complex challenges such as climate change and preserving the health of humans, animals, plants and the environment require structured and holistic solutions enabled by systemic thinking.

Expert organizations such as AGES (Austrian Agency for Health and Food Safety) and GÖG (Austrian National Public Health Institute) make a significant contribution to health and health maintenance in Austria. Nevertheless, there are health threats that cannot be solved separately, as became clear during the COVID-19 pandemic. Even before, but especially during the pandemic, there was increased cooperation. The ad hoc structures and activities created were successful in the short term but were not a solution in the medium and long term, as the focus was exclusively on SARS-CoV-2.

In order to respond better, faster and more efficiently to future threats, the WHO recommends using the inter-pandemic periods for cross-institutional cooperation. These phases offer the opportunity to improve coordination and resource management, to make the exchange of information more effective and to develop joint strategies and measures - at global, regional and national level.

For this reason, AGES and GÖG began working on a joint memorandum of understanding and cooperation agreement on One Health at the end of 2024 and it was signed beginning of 2025. As part of a task force, a common understanding of One Health is being developed, within a joint workshop common One Health topics were identified and next workflows agreed on. This structured collaboration is the first step towards an integrative One Health strategy for Austria.

Speaker: Barbara Kovacs (AGES, Österreichische Agentur für Gesundheit und Ernährungssicherheit)

10:30 AM Screening of shrews for Borna disease virus 1 (BoDV-1) and its implications for public health management

Borna disease virus 1 (BoDV-1) causes mostly fatal encephalitis in humans and other mammals. Its distribution area is restricted to parts of Southern and Eastern Germany, Austria, Switzerland and Liechtenstein. Spillover to dead-end hosts results from direct and/or indirect contact to bicolored white-toothed shrews (Crocidura leucodon), the natural BoDV-1 reservoir, which shed the virus via urine, feces, saliva and skin, but remain unaffected by the disease.
As part of this project, 263 shrews, predominately from Bavaria, were tested for BoDV-1 and their species was determined by a newly established RT-qPCR assay targeting the cytochrome b gene. Twenty-four (26.4%) of 91 C. leucodon as well as one out of 11 (9.1%) Mediterranean water shrews (Neomys anomalus) tested positive for BoDV-1, all of which originated from Bavaria. Phylogenetic analyses demonstrated the BoDV-1 sequences to belong to the same local clusters as found in Borna disease cases in the respective regions.
Several BoDV-1-positive shrews were found in human dwellings. Environmental samples were collected in five instances two to four weeks later, revealing low levels of BoDV-1 RNA but no infectious virus. In two cases, submitters had experienced close contact to excretions of BoDV-1-positive shrews, initiating post-exposure prophylaxis and 12-months of monitoring.
This One Health approach refines BoDV-1 risk areas and provides valuable insights into the poorly defined human-animal interface of BoDV-1 infection.

Speaker: Lea Lenhard (Institute of Diagnostic Virology, Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Greifswald - Insel Riems, Germany; Bavarian Health and Food Safety Authority, Munich, Germany; Zoonotic Bornavirus-Focal Point Bavaria (ZooBoFo) 2.0, Germany)

10:45 AM Psychological impact and perceived mpox risk among frontline healthcare workers during early epidemic phase, Uganda, August–September, 2024

On July 24, 2024, Uganda confirmed its first mpox outbreak, with initial cases detected in Kasese and Mayuge Districts. As a newly emergent disease, mpox posed unfamiliar clinical and operational challenges for healthcare workers (HCWs), whose limited experience and stigma surrounding the illness risked eroding confidence and undermining psychological well-being. To guide tailored support measures, we assessed risk perception and psychological distress among HCWs. We conducted a cross-sectional study during August–September 2024. Self-administered questionnaires were filled out by consenting day-shift HCWs: sociodemographic, occupational behaviors, perceived risks, and psychological distress variables. We determined the prevalence of psychological distress as the proportion of HCWs with a General Health Questionnaire score >12. A higher score from the 25 concern statements signified a higher degree of risk perception. We identified associated factors using modified Poisson regression. Overall, 339 HCWs participated at an 80% response rate; 215 (63%) were female, and 253 (75%) were aged 18-35 years. HCWs, 208 (61%), reported a moderate level of perceived risk. The prevalence of psychological distress was 26% (n=88, 95%CI=17–35%). Moderate perceived mpox risk (aPR=10, 95%CI=2.5–37) and high perceived risk (aPR=14, 95%CI=3.6–56) were associated with psychological distress. HCWs lacking infection prevention and control (IPC) confidence (aPR=1.2, 95%CI=1.0–1.5) and those without a clear health facility IPC plan (aPR=1.3, 95%CI=1.1–1.6) had increased likelihood of psychological distress. Psychological distress was common among HCWs during the study period, driven by perceived mpox risk and inadequate IPC measures. There’s a need to combine mental health support with strengthened IPC protocols through hands-on training and clear operational guidelines to protect HCW well-being and maintain uninterrupted service delivery during mpox and future outbreaks.

Speaker: Mrs Joyce Owens Kobusingye (Uganda National Institute of Public Health)

9:40 AM → 11:10 AM Session 10: Vaccines & Immunology + Novel Methods + AI in Health Research

Conveners: Michael Mühlebach, Torsten Semmler

9:40 AM Development of broadly protective Outer Membrane Vesicle based intranasal betacoronavirus vaccine

Background: After the initial outbreak of SARS-CoV-2, other (partially) immune escape variants appeared rapidly highlighting the need to develop a vaccine that offers a broader protection not only against SARS-CoV-2 variants but also to other members of the betacoronavirus genus. Furthermore, the present SARS-CoV-2 vaccines are administered intramuscularly and do not elicit mucosal immunity, which is deemed important for protection against SARS-CoV-2 infections.
Objective: Here, we develop a new intranasal pan-Betacoronavirus vaccine using Intravacc’s established Neisseria meningitis derived Outer Membrane Vesicles (OMV), where the vesicle serves as carrier for viral antigens.
Methods and Results: As a first step, 75 candidates consisting of full spikes, chimeric spikes and Receptor Binding Domain concatemers (RBDs) were designed using 4 sarbecoviruses, 3 merbecoviruses and 4 embecoviruses pre- selected spike sequences. 44 proteins were successfully synthesized and screened by Enzyme linked immunosorbent assay (ELISA) using human sera that were pre-characterized for high titre-pan-coronavirus reactivity by Immunofluorescence assay (IFA). Subsequently, a pool of 22 vaccine candidates consisting of high and low reactive spikes along with 3 binary combinations of proteins were recommended for mice immunogenicity study. For the immunogenicity study, 10 BALB/cOlaHsd mice were vaccinated intranasally on day 0 and day 21 with 20µl of vaccine. The mice were sacrificed on day 35 under anaesthesia and their sera and lung homogenate were analysed. Pooled sera from the mice immunogenicity study were tested for neutralization (1:10-1:1280) against SARS-related CoV, SARS-CoV-2 and MERS-CoV Vesicular stomatitis virus pseudo_particles (VSVpp). Neutralization data showed that 4 candidates; a trimeric RBD concatemer, a hexameric RBD concatemer and 2 binary combination candidates consisting of MERS spike proteins and sarbecovirus tetrameric RBDs elicited broad neutralization until 1:1280 dilution of sera against all 3 above mentioned VSVpp. Furthermore, ELISAs performed for the same candidates with lung homogenate confirmed the presence of IgA and IgG antibodies (102-104). Currently, animal challenge studies for the selected candidates are in progress.
Conclusion: This new platform of intranasal pan corona vaccine can offer early robust mucosal protection against betacoronavirus infections and has the potential for expansion to other novel corona viruses in the future.

Speaker: Dr Kaneemozhe Harichandran (Charité-Universitätsmedizin Berlin, Institute of Virology, Germany)

9:55 AM Development and Evaluation of a Bivalent Vaccine Candidate for the Protection of Pigs against Infections with Pseudorabies and Nipah Virus

Nipah virus (NiV) infections pose a serious health risk to humans and livestock in Southeast Asia (SEA). Due to its high fatality rate in humans, the absence of licensed vaccines or therapies, and its likelihood to cause severe outbreaks, NiV has been added to WHO’s Blueprint list of ‘priority diseases’. Here, we developed a bivalent vaccine candidate to protect pigs simultaneously from infections with pseudorabies virus (causing Aujeszky’s disease) and NiV, both circulating in SEA, by engineering the live attenuated PrV vaccine strain Bartha K61 to co-express NiV F and G glycoproteins. Immunogenicity in pigs has been successfully demonstrated by analysis of NiV- and PrV-specific T-cell and antibody responses.
Based on these data, the protective effect in pigs against infections with PrV and NiV will now be assessed. First, the NiV infection model in pigs was established in the high containment animal unit at the FLI. Twelve pigs at the age of 10-12 weeks were infected oronasally with NiV, and were observed for up to 22 days. No severe clinical signs were monitored, confirming findings from published studies. Animals were sampled daily until 10 days post infection (dpi) to assess viremia, viral shedding and immune responses. Necropsies of two pigs each were performed at 4,5,7,8,21 and 22 dpi to analyze the progression of viral dissemination especially at early time point after inoculation. These data will allow a targeted sampling during the planned vaccine efficacy studies.

Speaker: Anne Balkema-Buschmann (Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit)

10:10 AM Magnetic bioprinted granuloma: a three-dimensional model for cattle tuberculosis

Tuberculosis (TB) continues to represent a significant global health concern, impacting both humans and livestock. Mycobacterium bovis is the causative agent of bovine TB, an important zoonosis, whereas Mycobacterium tuberculosis, an organism adapted to humans, can occasionally cause symptomatic infection in cattle. The formation of granulomas, defined as organized multicellular tissue lesions, has been identified as a hallmark of TB in all affected host species. We developed a three-dimensional granuloma model, termed in vitro granuloma-like structure (IVGLS), using bovine leukocytes and magnetic nanoshuttles. Stable IVGLS were bioprinted to resemble either TB granulomas at innate stage, composed of macrophages, or the adaptive stage, containing also lymphocytes. M. bovis Bacillus Calmette-Guérin (BCG) replicated within the IVGLS, inducing foamy cell formation and triggering apoptosis particularly in the presence of lymphocytes. IVGLS released chemokines and Th1 cytokines and rewired their metabolism towards glycolysis. Cattle IVGLS recapitulate features of TB granulomas and facilitate spatial mapping of the immune responses.

Speaker: Anca Dorhoi

10:25 AM Establishing a human stem cell-derived infection model to visualize the effects of Listeria monocytogenes on the developing brain

Zoonotic infections during pregnancy, especially those involving the central nervous system, are associated with an increased risk for neurodevelopmental disorders in offspring. Listeria monocytogenes is a key example, with prenatal exposure linked to long-term neurological impairments. To investigate underlying pathogenic mechanisms, we employed a human induced pluripotent stem cell (iPSC)-derived neurosphere model that mimics key aspects of fetal brain development.
A standardized infection protocol was implemented: Bacteria were cultured to 10⁸ CFU/mL (OD 0.5) and applied at multiplicities of infection (MOI) of 50, 100, and 150 for 1–4 hours. Following gentamicin treatment to eliminate extracellular bacteria, neurospheres were fixed at 1, 24, and 48 hours post-infection. Infection was validated via immunofluorescence using Listeria-specific antibodies and Phalloidin to label actin filaments. Variable invasion patterns were observed across conditions, reflecting clinical heterogeneity. All MOIs supported successful infection; MOI 50 was selected for subsequent analyses, as it more closely reflects physiologically relevant infection levels. Infections were more consistent following 2-hour exposures compared to 1 hour. Viability exceeded 80% and cytotoxicity remained below 5% of controls, indicating the model’s suitability for studying host-pathogen interactions without compromising neurosphere integrity.
Ongoing studies will evaluate infected cell populations, proliferation, migration, and electrophysiological alterations.

Speaker: Annika Fischer (Institute of Pharmacology and Toxicology, School of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany; Institute of Food Quality and Food Safety, University for Veterinary Medicine Hannover, Hannover, Germany; Charité – Universitätsmedizin Berlin, Einstein Center for Neurosciences Berlin, Berlin, Germany)

10:40 AM Towards Real-Time Detection of COVID-19 via Untargeted Volatile Organic Compound Profiling Using Online Gas Chromatography-Ion Mobility Spectrometry

Volatile organic compounds in exhaled breath reflect metabolic alterations during viral infection, offering potential for rapid SARS-CoV-2 detection. We developed an online gas chromatography-ion mobility spectrometry (GC-IMS) method for direct breath analysis from 119 participants with RT-PCR confirmed COVID-19 status. Participants breathed directly into the GC-IMS instrument (STEP, Pockau, Germany) through a mouthpiece for 4 seconds, followed by 209 seconds analysis. The system utilizes a 20-meter MXT-5 GC column (at 60°C) with tritium IMS detector operating at 400 V/cm. Measurements at ambient conditions use filtered air as drift gas. Ambient air samples enable background subtraction reducing environmental confounding. The platform achieves ppb-ppt detection limits with a computational pipeline for spectral processing and analysis. Comprehensive metadata including dietary intake accounts for confounding factors. This untargeted approach aims to classify COVID-19 patients using machine learning on breath VOC profiles. Previous experimentation distinguished antibiotic-resistant bacteria with similar instrumentation (MCC-IMS) in in vitro tests. The method provides rapid (< 4 minutes ), non-invasive screening with real-time results, offering potential for point-of-care diagnostics and high-throughput pandemic applications.

Speaker: Deevanshi Walia (Fraunhofer IZI)

10:55 AM Tackling One Health risks – From current practice to future perspectives

Microbial Risk Analysis (MRA)—comprising risk assessment, risk management, and risk communication—plays a pivotal role in protecting public health and ensuring food safety across the globe. Yet, the accelerating transformation of food systems, the emergence of novel microbial hazards, and the growing recognition of One Health interdependencies increasingly challenge the effectiveness of traditional MRA frameworks. Globalization, climate change, antimicrobial resistance, and biodiversity loss are reshaping the dynamics of pathogen emergence and transmission along the human-animal-environment interface, demanding risk analysis approaches that are flexible, adaptive, and fit for these complex realities.
In this contribution, we critically examine the current state of microbial risk analysis and explore pathways toward its future evolution in line with the One Health paradigm. Drawing on a systematic literature review, insights from a global survey of food industry professionals, and a computational proof-of-concept study using AI-based agent modeling, we provide an integrated perspective on methodological gaps, practical challenges, and opportunities for innovation. Our findings confirm that Codex Alimentarius-aligned risk assessment remains the prevailing standard. However, across sectors, there is a growing call for participatory and integrated approaches capable of addressing the complexity of emerging risks and diverse food system contexts. Survey results highlight substantial variation in risk perceptions, implementation strategies, and decision-making processes, particularly influenced by company size, regulatory environments, and geographic region. Misconceptions such as the belief in the feasibility of “zero risk” further emphasize the need for improved communication and stakeholder engagement.
To help bridge these gaps, we showcase the potential of AI-supported, agent-based modeling to facilitate transparent risk negotiation and consensus-building across stakeholder groups. By aligning scientific rigor with inclusive, participatory processes, we argue that MRA can be strengthened as a central pillar of One Health, supporting informed decision-making and balanced solutions in the face of complex, cross-sectoral challenges. Our work advocates for the evolution of microbial risk analysis into a dynamic, collaborative, and digitally empowered discipline—better prepared to address the interconnected risks of our shared ecosystems.

Speaker: Dr Alexandra Fetsch (Competence Centre for Food Safety, Chair of Food Microbiology, LMU Munich)

11:10 AM → 11:30 AM Coffee & Poster Viewing

11:30 AM → 1:00 PM Session 11: Emerging Pathogens III + Conservation & Wildlife

Conveners: Fabian Leendertz, Magdalena Meyer

11:30 AM Comparative Immune Responses to Pathogenic and Non-Pathogenic Mammarenaviruses in Human and Reservoir-Derived Antigen-Presenting Cells

Mammarenaviridae is a genus of ambisense RNA-viruses, with members that cause viral hemorrhagic fever, namely Lassa virus (LASV) and Lujo virus (LUJV) and members that have not been associated with disease, such as
Mopeia virus (MOPV). LASV infection results in 5000 to 10,000 deaths annually in sub-Saharan Africa, and LUJV has a case-fatality rate of up to 80%. The Natal multimammate mouse (Mastomys natalensis, NMM) has been identified as a natural reservoir of LASV and MOPV. However, these animals do not show clinical signs upon infection. In humans, LASV targets dendritic cells (DCs) and macrophages (MΦs), among other cells, and induces activation and maturation of DCs, but downregulates interferon response and fails to induce robust T-cell responses.
Given the lack of pathology of LASV infection in NMM, and the pivotal role of DCs and MΦs in the disease development in humans and non-human primates, the purpose of our study is to compare the immune profile of human and NMM-derived DCs and MΦs responses LASV, LUJV and MOPV infection. We differentiated DCs and MΦs from bone-marrow cells isolated from adult NMM or human monocytes and infected them with LASV, LUJV or MOPV. We sampled cells and supernatants at 2 days post-infection. As controls for the activation of the innate immune response in these cells, we stimulated the cells Sendai virus (SeV). We performed a characterization of immune profile of the cells the cells,
measured the transcript levels of immune-related genes and quantified viral loads. We describe the comparative immune-profile resulting of the infection with pathogenic vs. non-pathogenic Mammarenaviruses, in human and in a natural reservoir species. This gives us insights on the mechanisms of pathogenesis in humans and protection for the natural reservoir species. This highlights the importance on the insights on the immune mechanism that lead to a non-pathogenic infectious phenotypes and the relevance for natural reservoir's further studies.

Speaker: Nicolas Corrales (Robert Koch Institut)

11:45 AM Genomic characterization and mapping of molecular factors driving the increased replication fitness of Arabian MERS-CoV lineage B5

MERS-CoV is a highly pathogenic Betacoronavirus with a ~36% case-fatality rate and a zoonotic origin in dromedary camels. Clade B strains circulate in the Arabian Peninsula and are the primary cause of severe human infections, leading to sporadic outbreaks. In recent years, different clade B lineages have emerged, with lineage B5 replacing other clade B strains in the Middle East. Lineage B5 strains exhibit increased replicative fitness, higher resistance to type I interferons (IFNs), and reduced host immune activation, indicating enhanced viral fitness. Comparative genomic analyses with lineages B3, B4, and the EMC strain (clade A) reveal that B5 strains accumulate genetic changes, particularly in nsp3 and the Spike gene. To identify genetic determinants of B5 fitness, we used a reverse genetic system based on transformation-associated recombination (TAR) cloning. This system enables precise mapping of functional differences between recombinant MERS-CoVs. We generated 12 chimeric viruses by systematically exchanging genomic fragments between a lineage B5 strain and EMC. These were screened for replicative competence in Calu-3 cells, with or without type I IFN pre-treatment. Initial results suggest that genetic polymorphisms acquired in nsp3 and Spike could be responsible for the enhanced virulence of lineage B5 strains. Further assays are currently ongoing to depict specific virulence mechanisms and link them to fixed polymorphisms in B5 strains.

Speaker: Annika Beyer (Charité Institut für Virologie, Humboldt Universität zu Berlin)

12:00 PM Deciphering Lineage-Specific Determinants of Usutu Virus through Targeted prM/E Substitutions

Usutu virus (USUV) is an emerging mosquito-borne flavivirus that primarily affects birds but can also cause neuroinvasive disease in humans. Despite the growing number of outbreaks and increasing concern, many aspects of its biology remain poorly understood. Several viral lineages have been identified, but a systematic comparison of mutations within the pre-membrane (prM) and envelope (E) proteins has not yet been conducted. To investigate the functional impact of prM/E protein variations, we engineered a panel of six recombinant USUV strains using a common genetic backbone derived from aEU2 lineage strain. Within this conserved scaffold, the prM/E coding regions were replaced by reverse genetics with those from representative lineages, allowing for an in-depth evaluation of lineage-specific differences in these critical structural proteins. The resulting viruses are being extensively characterized in vitro in mammalian and mosquito cell lines, and in vivo experiments have been planned. Additional characterization is being conducted in ovo to explore infection dynamics in a vertebrate model. Embryonated chicken eggs are sampled over 5 days, and tissues are harvested for downstream analyses. Altogether, this comprehensive dataset is expected to provide valuable insights into the effects of prM/E mutations on key viral traits, contributing to a better understanding of USUV pathogenesis, host interaction, and lineage-specific phenotypes.

Speaker: Marialuigia Caporale (Experimental Zooprophylactic Institute of Abruzzo and Molise (IZSAM), Teramo, Italy. PhD National Programme in One Health approaches to infectious diseases and life science research, Departiment of Public Health, Experimental and Forensice Medicine, University of Pavia, Pavia, 27100, Italy)

12:15 PM Prevalence and associated factors of post-traumatic stress disorder, depression and anxiety disorders among mpox survivors, Uganda, 2024

Background: Mpox was declared an epidemic in Uganda on July 24, 2024. By December 30, 2024, approximately 800 mpox cases were reported across 53 districts, with Kampala Metropolitan Area (KMA) bearing two-thirds of the burden. Mpox response in Uganda is still deficient in aspects of mental health support to case-patients or survivors. We assessed the prevalence and associated factors of anxiety, depression, and posttraumatic stress disorder (PTSD) among mpox survivors in the most affected districts in Uganda.
Methods: This was a cross-sectional community-based study conducted from February 1–28, 2025. We selected respondents using simple random sampling of survivors from Kampala, Mukono, and Wakiso districts. The sampling frame were the lists of survivors from each of the 3 districts. Random numbers generated from excel were used to select participants for the study. Sample size was determined using Kish Leslie formula assuming a 50% prevalence of mental health disorder among survivors. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale, while PTSD was evaluated with the PTSD Checklist DSM-5. Associated factors for each condition were determined using modified Poisson regression. The threshold for probable presence based on reported symptoms (caseness) for anxiety and depression was 8 and that of PTSD was 38.
Results: We enrolled 385 participants with a median age of 29 years (IQR: 25–35). A total of 230 (60%) were female, and 136 (59%) of these were female sex workers. The caseness prevalence of anxiety was 11% (95%Cl 8%–14%), depression was 14% (95%CI 11%–18%) and PTSD was 9% (95%CI 6%–12%). The general caseness prevalence of mental health disorders among mpox survivors was 22% (n=84; 95% CI 18%–26%). Factors associated with increased prevalence of mental health disorders were longer stay (>14 days) at the treatment unit (aPR=2, 95%CI 1.3–3.1), reports of poor management at the treatment unit (aPR=2.7, 95%CI 1.3–3.1), having suffered moderate (aPR=2.2, 95%CI 1.2–4.3) or severe (aPR=5.6, 95%CI 3.1–10.2) symptoms of mpox and having suffered stigmatization from society (aPR=2.2, 95%CI 1.4–3.6).
Conclusions: Approximately 2 in 10 mpox survivors surveyed experienced significant symptoms of a mental health disorder during the illness or recovery. These findings underscore the need for integrated mental health and psychosocial support in mpox outbreak responses to address the psychological impacts of affected persons.

Speaker: Emmanuel Okiror Okello (Uganda Public Health Fellowship Program, Uganda National Institute of Public Health, Kampala, Uganda)

12:30 PM 90 kDa ribosomal S6 Kinase 1 influences endosomal acidification during Influenza A virus infection

RSK kinases belong to the downstream targets of the classical MAPK/ERK pathway, which contributes to the release of the influenza virus (IV) genome via endosomal acidification. Here we show for the first time, that the kinase isoform RSK1 is also involved in this process.
Inhibition of RSK with the inhibitor BI-D1870 or siRNA mediated knockdown of RSK1 resulted in a decreased internalization of VSV-pseudotyped H1N1 viruses as well as endosomal acidification (EA). Super resolution microscopy (STED) and proximity ligation assays (PLA) revealed that not only ERK but also RSK1 colocalizes with the late endosomal marker CD63.
EA is controlled by v-ATPases which are phosphorylated by ERK or PI3K. We hypothesized that RSK1 also takes part in this process and found colocalization of RSK1 with the v-ATPase subunit A.
In conclusion, this work demonstrates, that RSK1 is misused by human IV and HPAIV in an isoform specific manner to promote the release of the viral genomes in the cytoplasm.

Speaker: Nicole Oberberg (Institute of Virology, UKM Münster)

12:45 PM Detection of Nairobi Sheep Disease Virus in Goats and Sheep and of Two Previously Unknown Nairoviruses in Rodents and Shrews in Uganda’s Albertine Rift

The genus Orthonairovirus contains tick-borne viruses with public and veterinary health importance, such as Nairobi Sheep Disease Virus (NSDV) which causes febrile illness in humans and lethal haemorrhagic gastroenteritis in goats and sheep with mortality rates of 90%. The aim of this study was to get insight into the genetic diversity of nairoviruses circulating in Uganda. Blood from cattle (n= 1064), goats (n= 1441), sheep (n=286), pigs (n=81), rodents and shrews (n=447) was collected in six areas in the Albertine rift valley in proximity to protected biodiversity hotspots and analysed using ultra-high-throughput sequencing and RT-PCR. NSDV was detected in 5 goats and 2 sheep from sampling sites across the rift valley, including Arua and Kasese Towns, as well as Semuliki and Bwindi Impenetrable National Parks. Complete NSDV genome analyses revealed nucleotide diversities of 0.5-25% to L, M and S segments of other NSDV strains. Further, two previously unknown nairoviruses were identified in rodents and shrews: one found in Bwindi Impenetrable National Park (n=3), and the others in Semuliki and Queen Elizabeth National Parks (n=5). The two novel viruses showed 85% pairwise nucleotide identities in their RdRp genes and maximal 65% pairwise identities to other rodent- and shrew-associated nairoviruses. These findings highlight the circulation of NSDV in goats and sheep and the presence of new nairoviruses in wildlife in Uganda, underscoring the need for an integrated One Health surveillance to prevent outbreaks.

Speaker: Mr Erick E. B. Kigai (Makerere University Kampala)

11:30 AM → 1:00 PM Session 12: Vectors

Conveners: Stefanie Becker, Sven Poppert

11:30 AM Simultaneous and Sequential Co-Infections with West Nile Virus and Usutu Virus in Culex pipiens biotype molestus

The epidemiological and geographical co-circulation of West Nile virus (WNV) and Usutu virus (USUV) poses the risk of potential co-infection in mosquito vectors. To investigate possible effects of co-infections in mosquitoes on the transmission of both viruses, a laboratory colony of Cx. pipiens biotype molestus was co-infected with WNV lineage 2 and USUV Europe 3, either simultaneously or sequentially in intervals of 7 days. Fourteen days after the last infection, infection and transmission were assessed.
After simultaneous co-infection, WNV transmission was increased compared to mono-infection, while USUV transmission was significantly reduced. In addition, WNV viral loads in mosquito bodies were significantly increased in mosquitoes with a concurrent USUV infection.
Similar effects on WNV loads were found in case of a WNV infection following a previous USUV infection; however, no significant impact on vector competence for USUV or WNV was observed. Initial experiments with a USUV infection after a previous WNV infection show a possible negative impact on USUV infection, indicating that WNV can outcompete USUV in any type of co-infection. Furthermore, possible negative effects of virus infection on mosquito fitness during sequential coinfection were observed, based on survival rates and biting behavior.
Further experiments will provide additional insights into the dynamics of WNV and USUV co-infections in mosquitoes, enabling risk assessment for regions with co-circulation.

Speaker: Christin Körsten (Friedrich-Löffler-Institut, Institute of Infectology)

11:45 AM A Multi-Ecosystem Analysis of the Links Between Land-Use Change, Mosquito Communities, and Virus Abundance

The emergence of mosquito-borne viruses is linked to land-use change and biodiversity loss, yet the ecological mechanisms driving these interactions remain poorly understood. This study aimed to identify common drivers for mosquito-borne virus emergence by studying the impact of land-use change on mosquito and virus community dynamics across lowland and montane rainforests and savannah.
A total of 32,632 mosquitoes, representing 130 species of 13 genera, were collected in disturbed and undisturbed sites. Mosquito species richness was significantly higher at undisturbed sites, with turnover rather than nestedness driving community differences across ecosystems. In total, we detected 665 viral sequences from 150 species, including 127 putative previously unknown viruses. Virus richness was higher at all undisturbed sites with more complex host-virus networks suggesting that land-use change homogenises mosquito-virus interactions, potentially altering transmission dynamics. Temperature was a key driver for mosquito abundance and diversity. Mosquito diversity correlated with virus diversity across ecosystems.
These findings highlight the role of vector communities in shaping viral communities. By using a multi-vector, multi-pathogen approach and integrating ecosystem-wide comparisons, this study advances our understanding of how anthropogenic disturbance influences vector-virus interactions and viral spread, with implications for public health and biodiversity conservation.

Speaker: Selina Graff

12:00 PM Studies on the co-localization of TBE-Virus and Borrelia species at selected TBEV-foci in Baden-Wuerttemberg

Ixodes ricinus is the main vector of several zoonotic pathogens in Central Europe, including Tick-Borne Encephalitis Virus (TBEV) and Borrelia burgdorferi sensu lato. Both are of major public health concern and call for integrated One Health surveillance. While co-circulation is known, co-localization in individual ticks remains largely unexplored.
In this study, 4587 ticks were collected in 2023–2024 from three confirmed TBEV microfoci and two TBEV-free sites in Baden-Wuerttemberg, Germany, and screened for both pathogens using molecular methods. TBEV-RNA was detected in 15 ticks and six of them (40%) were co-infected with different Borrelia species, mainly B. afzelii. Co-infections occurred in both nymphs and adult females.
Borrelia spp. prevalence across all sample sites ranged from 22% to 29%. The species detected were B. afzelii, B. garinii, B. valaisiana, B. burgdorferi s.s., B. lusitaniae and B. miyamotoi. Species composition was analyzed and compared between TBEV-endemic and TBEV-free sites.
These findings provide new evidence for the co-localization of human-pathogenic organisms in individual ticks. Co-infections may be more common than previously assumed and should therefore be considered both in diagnosis and in risk assessment.

Speaker: Ms Rebecca Vogt (University of Hohenheim, Department for Parasitology)

12:15 PM Plasticity in Thermal Tolerance, Vector Competence, and Metabolomic Responses of Culex pipiens under Seasonal and Microclimatic Variation

Due to global warming, vector-borne diseases are spreading worldwide. West Nile virus (WNV) outbreaks in Germany have increased since 2019, typically linked to hot summers. The main vector of WNV in Central Europe is the Culex pipiens species complex. While its role in transmission is well known, little is understood regarding how Culex pipiens responds physiologically and metabolically to heatwaves, raising questions about its climate resilience. We sampled six Culex pipiens populations along two urban-to-rural gradients in west and east Germany and across two seasons to assess survival and vector competence for WNV. To better understand their heat response, metabolomes of all populations were also analysed. Using random forest models, we evaluated the influence of biological factors (e.g. sex), climatic variables (micro- and macroclimate), and the experimental design (e.g. season) on heat survival and vector competence. Heat survival was affected by sex, age, season, and pre-oviposition microclimate, while vector competence was affected by season and especially the microclimate. Metabolomic profiling revealed differences between heat-treated and control individuals, as well as between populations, with the northernmost population possessing a distinct metabolic signature. These findings highlight the plasticity of thermal tolerance, metabolic response, and vector competence in Culex pipiens, with implications for WNV transmission under climate change.

Speaker: Isabelle Kramer (Goethe University Frankfurt)

12:30 PM Vectors on the rise – survivability of R. sanguineus s.l. in Germany

Changing temperatures and climate conditions led to expanding distribution areas and endemization of alien species in recent years. Rhipicephalus sanguineus s.l. is globally distributed and endemic in the Mediterranean region in Europe. Due to its close contact to dogs as hosts and its adaptation to dry and warm areas R. sanguineus s.l. is frequently introduced to Germany by vacationers with dogs and imported rescue dogs. These introductions led to infestations of homes including tick reproduction. Based on several reported autochthonous infestations, the question arose as to whether R. sanguineus s.l. survives in the field and possibly even form stable populations. Therefore, the ability of the two most frequently introduced species (R. sanguineus s.s. and R. linnaei) to survive under climatic conditions in Germany inside an experimental setup as close to nature as possible was investigated. For this purpose, the survivability of all developmental stages as well as of engorges females, the oviposition and the hatchability of egg masses was documented in weekly intervals from February 2023 to May 2024. R. sanguineus s.s. exhibited longer average survival time than R. linnaei at all developmental stages, whereas R. sanguineus s.s. survived outdoors for up to 44 weeks. Engorged females of both species successfully laid eggs from which viable larvae hatched. However, no stage of either species was able to survive the winter period (Nov. to Feb.) for more than 2–4 weeks.

Speaker: Katrin Fachet-Lehmann (University of Hohenheim, Parasitology)

12:45 PM Vector Behavior meets Transcriptomics: A Case Study of Ixodes ricinus and Harz Mountain Virus

Ticks are important vectors of emerging viruses, including the Jingmenvirus Alongshan virus strain Harz Mountain (ALSV_HM), recently identified in Ixodes ricinus ticks collected from game animals in Lower Saxony, Germany. To investigate the transcriptomic impact of ALSV_HM, adult I. ricinus were experimentally infected via intrathoracic injection and incubated for seven days. Subsequently, RNA sequencing was performed, and reads were aligned to the Ixodes scapularis genome. Infected ticks showed significant upregulation of gene transcripts related to immune response, intracellular signaling, and RNA/DNA-binding functions, suggesting a broad activation of antiviral pathways and transcriptional regulation. Transcripts encoding transport- and membrane proteins were downregulated, implying potential disruption of cellular homeostasis and molecular transport. Interestingly, transcripts associated with aggressive behavior in other arthropods were also differentially expressed. To test behavioral changes, vertical and horizontal repellency assays using Icaridin were used. ALSV_HM-infected ticks displayed reduced sensitivity to Icaridin during vertical questing, whereas horizontal movement remained unaffected. These findings suggest that ALSV_HM alters both gene expression and host-seeking behavior in I. ricinus, potentially enhancing transmission dynamics and underscoring the need for surveillance of novel tick-borne viruses in a changing environment.

Speaker: Paula Hornauer (Stiftung Tierärztliche Hochschule Hannover)

1:00 PM → 2:00 PM Lunch

2:00 PM → 2:30 PM Keynote VI: Jan Felix Drexler: Novel bat morbilliviruses at the domestic-wild animal interface

Conveners: Kevin Ciminski, Lisa Oestereich

2:30 PM → 3:30 PM Poster Prize & Farewell

Conveners: Fabian Leendertz (HIOH Greifswald), Sascha Knauf (Friedrich-Loeffler-Institut)