Back

Transboundary and Emerging Diseases

Wiley

Preprints posted in the last 90 days, ranked by how well they match Transboundary and Emerging Diseases's content profile, based on 34 papers previously published here. The average preprint has a 0.03% match score for this journal, so anything above that is already an above-average fit.

1
Integrated epidemiological and genomic analysis of some respiratory Bovine Coronavirus isolates reveals circulation of GIIb strains and ongoing viral evolution in U.S. Cattle (2020-2025)

Shah, A. U.; Varga, C.; Guger, P.; Hemida, M. G.

2026-03-13 microbiology 10.64898/2026.03.12.711484 medRxiv
Top 0.1%
17.7%
Show abstract

Bovine coronavirus (BCoV) is an important contributor to the respiratory disease complex in cattle; however, integrated genomic and epidemiological data describing currently circulating respiratory BCoV strains in the United States remain limited. The objective of this study was to monitor respiratory BCoV at the genomic level and analyze its epidemiological patterns over a five-year period. A total of 4,505 respiratory samples submitted to a diagnostic laboratory between January 2020 and November 2025 were analyzed, of which 693 (15.38%) tested positive for BCoV. Positivity was highest in young calves (0-40 days; 20.0%) and declined significantly with increasing age based on logistic regression analysis. Temporal trend analysis using LOESS smoothing and the Mann-Kendall test showed no significant monotonic change in BCoV detection during the study period. Co-infection analysis indicated that BCoV was commonly detected with other viral respiratory pathogens, while bacterial pathogens predominated in many samples. Lung tissues from infected cattle were screened by RT-PCR, and selected samples with high viral loads were subjected to next-generation sequencing. Complete genome sequencing identified four respiratory BCoV isolates ([~]31 kb), all clustering within genotype GIIb with recent U.S. strains. Comparative genomic analysis revealed several amino acid substitutions in structural and non-structural proteins that may influence viral attachment, replication, and tissue tropism. These findings provide updated epidemiological and genomic insights into respiratory BCoV circulating in U.S. cattle.

2
Spatiotemporal dynamics of β-lactam-resistant E. coli in young diseased calves in Wallonia, Belgium

Guerin, V.; Cabanel, N.; Meijer, G. M. M. D.; Royer, G.; Mainil, J. G.; Duprez, J.-N.; Salmon, M.; Thiry, D.; Glaser, P.

2026-01-21 microbiology 10.64898/2026.01.21.700780 medRxiv
Top 0.1%
17.2%
Show abstract

Calves are one of the most common carriers of antibiotic-resistant bacteria among farm animals. However, the impact of antibiotic usage on resistance mechanisms, transmission routes between farms, and the transmission of resistant bacteria to humans remain largely unknown. Here we analyzed the population of {beta}-lactam resistant E. coli isolated over five calving seasons on 444 farms scattered throughout Wallonia, Belgium. Restrictions on critical antibiotics usage led to a reduction of resistance to 3rd generation cephalosporins but has no impact on population structure and {beta}-lactamase genes indicating a resilient population. The correlation between short genetic distances and geographic proximity suggests indirect transmission between farms by fomites with differences between regions east and west of the river Meuse. Phylogenetic analysis of calf isolates with isolates from public databases indicates transitions from bovine to human adaptation. These findings provide new means to further model the spread of E. coli in livestock farming.

3
Buffaloed in Brandenburg: Germany's first Brush with Foot-and-Mouth Disease after four Decades of Freedom

Eschbaumer, M.; Staubach, C.; Pfaff, F.; Gethmann, J.; Schulz, K.; Rogoll, L.; Bock, S.; Bock, W.-I.; Schulze, C.; Marquart, R.; Reinhardt, N.; Nickisch, S.; Kakerow, N.; Freter, S.; Rudovsky, A.; Albrecht, K.; Leo, S.; Haarmann, C.; Lenz, S.; Hoffmann, B.; Calvelage, S.; Höper, D.; Zitzow, P.; Breithaupt, A.; Cokcaliskan, C.; Parlak, U.; Karniely, S.; Abdulrasool, L. M. S.; Knowles, N.; Girault, G.; Romey, A.; Bakkali, L.; King, D. P.; Kühn, C.; Sauter-Louis, C.; Beer, M.

2026-03-31 microbiology 10.64898/2026.03.30.713672 medRxiv
Top 0.1%
14.4%
Show abstract

Foot-and-mouth disease (FMD) virus is one of the most feared and most consequential pathogens of livestock worldwide. It can be spread rapidly by the transboundary movement of animals, animal products and byproducts. In January 2025, Germany detected its first FMD outbreak since 1988 in extensively reared water buffalo on a small farm in the state of Brandenburg, directly outside Berlin, the federal capital. Immediate control measures including a standstill for movements of susceptible animals and pre-emptive culling were implemented by the veterinary authorities. Whole-genome sequencing identified the virus as serotype O, topotype ME-SA, lineage SA-2018 and revealed extensive recombination, but cross-neutralization assays suggested good heterologous protection by an O/PanAsia-2 vaccine strain. Epidemiological back-calculation placed the time of virus introduction in late December 2024. Although the entry route remains unresolved, human-associated introduction is most likely. Network analysis revealed minimal farm connectivity, and simulations predicted low potential for onward transmission, which is consistent with the outbreak being ultimately restricted to a single herd. This event underscores the constant and unpredictable risk of introduction of the virus. Early detection through increased awareness and comprehensive differential diagnostics as well as the international collaboration of veterinary services, laboratories and experts are essential in the face of the global presence of FMD.

4
Timing the regional spread of PRRSV-2 variants across the United States

Herrera da Silva, J. P.; Paploski, I.; Kikutu, M.; Pamornchainavakul, N.; Corzo, C.; VanderWaal, K.

2026-03-13 ecology 10.64898/2026.03.12.711334 medRxiv
Top 0.1%
14.0%
Show abstract

Porcine Reproductive and Respiratory Syndrome Virus 2 (PRRSV-2) represents a major threat to the global swine industry. The epidemiological dynamics of PRRSV-2 are characterized by the recurrent annual emergence of dozens of variants. Long-distance spread of PRRSV-2 is largely driven by animal shipments. Spatiotemporal dynamics of PRRSV-2 in the USA have been explored; however, how fast variants spread to new regions after their emergence remains unclear, and this information could improve preparedness. To address this, we analyzed 14,835 sequences, retrieved from the Morrison Swine Health Monitoring Project (MSHMP), representing 156 variants sampled from 2015 to 2024, covering the five major swine-producing regions in the USA: the Upper Midwest (UM), Lower Midwest (LM), Atlantic Seaboard (AS), Northeast (NE), and Great Plains (GP). Time to spread was assessed using the time-to-dispersal event analysis and waiting time analyses. Genetic diversity was measured using Hill numbers. The UM had the highest variant richness (n=123), followed by the LM (n=47), AS (n=35), NE (n=45), and GP (n=38). Of the 62 variants that initially emerged in the UM, 17 later spread to other regions. The UM also received the highest number of variant introductions (n=24), followed by LM (n=14), NE (n=14), AS (n=4), and GP (n=7), highlighting regional differences in connectivity and risk. Our results suggest faster dispersal corridors among interior regions (e.g., GP to UM and LM to UM, [~]1.2-2.0 years) and slower for coast to interior pathways (AS to interior, [~]2-3 years). These findings may help anticipate the risk of PRRSV-2 variant introduction and provide more accurate dispersal time estimates, which are useful for improving epidemiological models and disease preparedness.

5
Prevalence of Mycoplasmopsis agassizii across wild and captive Mediterranean tortoises

Canos-Burguete, M.; Gimenez, A.; Martinez-Silvestre, A.; Budo, J.; Marschang, R. E.; Sanchez-Ferreiro, B.; Rodriguez-Caro, R.; Gracia, E.

2026-03-12 ecology 10.64898/2026.03.11.710774 medRxiv
Top 0.1%
14.0%
Show abstract

Mycoplasmopsis [Mycoplasma] agassizii is one of the principal pathogens associated with upper respiratory tract disease (URTD) in tortoises, yet its epidemiology in European wild chelonian populations remains poorly understood. The pathogen has been linked to population declines in some wild tortoise populations and is frequently detected in captive tortoises, where infections may persist subclinically and prolonged contact can facilitate transmission. In this context, the pet trade and the release or escape of captive individuals represent potential pathways for pathogen exchange between captive and wild populations. We assessed the presence and prevalence of M. agassizii in wild Mediterranean tortoises in Spain and compared infection patterns with captive populations. A total of 259 tortoises were sampled between 2020 and 2025, including spur thighed tortoises (Testudo graeca; 127 wild; 63 captive) and Hermanns tortoises (Testudo hermanni; 46 wild; 23 captive). Detection of M. agassizii was performed using PCR. The pathogen was detected in both species, but prevalence patterns differed markedly between captivity status and species. High prevalence was consistently observed in captive individuals of both species. In contrast, wild populations showed species-specific patterns: T. graeca exhibited very low or absent prevalence across wild populations, whereas T. hermanni showed comparatively higher prevalence in the wild. These results provide the first baseline assessment of M. agassizii occurrence in Mediterranean tortoises in Spain and highlight the importance of incorporating pathogen surveillance into conservation and management strategies for European chelonian populations.

6
Spatiotemporal clustering of highly pathogenic avian influenza (HPAI) H5N1 at the wild waterfowl-poultry interface: Vector-specific spillover risks in the U.S., 2022-2025

Varga, C.

2026-03-07 microbiology 10.64898/2026.03.06.710020 medRxiv
Top 0.1%
12.2%
Show abstract

BackgroundThe emergence of the highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b in North America, beginning in February 2022, has highlighted the dynamic, unpredictable, and regionally variable risk of infections. Studies are needed to assess the spatiotemporal clustering of HPAI H5 at the interface between wild waterfowl and commercial poultry to better understand and mitigate this risk. MethodsPublicly available data on HPAI H5 detections in wild birds and commercial poultry from January 2022 to January 2026 were analyzed at the county level. Retrospective space-time permutation models were used to identify and scan for clusters with higher than expected detection rates. ResultsA total of 17,091 HPAI H5 detections were reported in wild birds across 1,467 county-level locations. Four species, Mallard (Anas platyrhynchos) (2,848 detections, 16.66%), Canada goose (Branta canadensis) (1,496, 8.75%), Green-winged teal (Anas carolinensis) (1,364, 7.98%), and Snow goose (Anser caerulescens) (1,084, 6.34%), accounted for 39.73% of detections. In commercial poultry, 532 outbreaks in turkey operations, 148 outbreaks in table-egg layer operations, 99 outbreaks in broiler chicken operations, and 89 outbreaks in commercial duck operations were reported, respectively. Several spillover events followed an east-to-west expansion. In early 2022, mallard detections preceded outbreaks in Northeast egg-layer and duck farms, while snow goose detections in the Upper Midwest coincided with turkey farm outbreaks. In the Pacific and Mountain West during summer 2022, detections in Canada geese overlapped with turkey farm outbreaks. A resurgence occurred in the Midwest (2025), with snow and Canada goose detections overlapping severe outbreaks in turkey and layer flocks. Additionally, in the Upper Midwest, Canada goose and mallard detections overlapped with outbreaks in commercial duck farms during fall-winter 2025. ConclusionsThe study findings demonstrate distinct vector-based transmission dynamics of HPAI H5 at the wild waterfowl-poultry interface. Farm biosecurity strategies must adapt to these recurrent, vector-specific risks.

7
Geostatistical mapping of transboundary cattle disease risks in Ethiopia

Gizaw, S.; Desta, H.; Wieland, B.; Knight-Jones, T.

2026-02-27 ecology 10.64898/2026.02.27.708445 medRxiv
Top 0.1%
10.2%
Show abstract

Ethiopia experiences devastating economic losses from an ongoing endemic burden of trans-boundary animal diseases (TADs). TADs are highly transmissible infectious diseases of animals, often able to spread rapidly with significant economic and public health consequences. Contagious bovine pleuropneumonia (CBPP), foot-and-mouth disease (FMD), and lumpy skin disease (LSD) are among the global priority TADs for cattle. In this study, we used responses from a survey about cattle disease delivered to livestock keepers across Ethiopia. We used generalized additive mixed models applying neighborhood cross-validation method which accounts for spatial dependence in the data to investigate the spatially variable relationships between bioclimatic variables and distribution of CBPP, FMD, and LSD in Ethiopia. We also developed model-based risk maps of these diseases using a geostatistical kriging method to guide knowledge-based decision making. The results show the risks of CBPP vary with altitude and relative humidity, risks of FMD with temperature and relative humidity, and of LSD with temperature and precipitation. The gaussian spatial smooth terms are all significant. The maps are produced using rigorous statistical analysis with very low prediction errors and can thus be considered reliable. Our results have implications for the impacts of climate change, and the vulnerability of communities in high-risk areas. The risk maps illustrate how such maps contribute to climate-informed disease early warning systems.

8
Prevalence and Molecular Detection of Pasteurella multocida, Mannheimia hemolytica, and Bibersteinia trehalosi in Sheep, Western Oromia, Ethiopia

Gemechu, M. K.; Hambisa, A. B.; Sima, D. M.

2026-02-18 molecular biology 10.64898/2026.02.16.706086 medRxiv
Top 0.1%
10.1%
Show abstract

Ethiopia has the biggest population of livestock in Africa, and small ruminants play a significant role in both meat consumption and revenue from the export of live animals and their skins. Infectious diseases, especially pneumonic pasteurellosis, are a key constraint in productivity, which is low despite their economic relevance for a variety of technological and non-technical reasons. Sheep are particularly susceptible to high rates of morbidity and mortality from the disease while under stress. These bacterial species were to be isolated, identified, and molecularly detected from sheep in certain regions of western Oromia, Ethiopia, that appeared to be healthy, as well as those that were clinically ill. Using multi-stage sampling, a cross-sectional study was carried out in three zones: Horro Guduru Wollega, East Wollega, and West Shawa, between January and December 2022. 384 sheep (220 healthy, 164 ill) had their nasal swabs taken, and they were analyzed bacteriologically, biochemically, and molecularly using PCR for the PHSSA, Rpt2, and CapA genes. To evaluate the relationships between risk factors and bacterial prevalence, data were examined using logistic regression and descriptive statistics. With P. multocida being the most commonly isolated species, followed by M. haemolytica and B. trehalosi, the overall prevalence of Pasteurellaceae was 21.1%. Pneumonic and young sheep had a greater prevalence, and there were significant correlations with age (OR = 2.41; 95% CI: 1.42-4.18) and illness status (OR = 3.47; 95% CI: 2.06-5.97), but not with sex or location. These results demonstrate the persistent risk of pneumonic pasteurellosis in Ethiopian sheep and the significance of species-level identification in directing focused interventions, such as management, treatment, and immunization plans. To molecularly describe isolates from other places and elucidate the pathogenic function of Pasteurella and Mannheimia species in illness development, more research is advised.

9
Molecular Diversity and Recombination Patterns of the ORF7 (Nucleocapsid) Gene in Betaarterivirus americense Variants Circulating from Lima, Peru

Cotaquispe, R. Y.

2026-02-26 molecular biology 10.64898/2026.02.24.707833 medRxiv
Top 0.1%
8.4%
Show abstract

Porcine reproductive and respiratory syndrome (PRRS) is a globally distributed disease caused by Betaarterivirus europensis (PRRSV-1) and Betaarterivirus americense (PRRSV-2). Its clinical presentation ranges from subclinical infection to severe disease, depending on viral evolution and the emergence of novel variants. The aim of this study was to characterize the genetic diversity and identify recombination events in the ORF7 (nucleocapsid, N) gene of ten PRRSV-2 strains circulating in pig farms in Lima, Peru. Bioinformatic analyses were performed using DNAMAN v10.0, MEGA 6, BepiPred-2.0, DnaSP v6, and RDP v4.101. Phylogenetic analysis revealed two well-defined lineages: eight strains clustered within lineage 1A (NADC34-like), and two within lineage 5A (VR2332-like), demonstrating the co-circulation of genetically distinct variants in the region. Comparative sequence analysis identified significant amino acid substitutions in eight strains (15, 16, 17, 20, 21, 22, 23, and 24), with strain 24 being the most divergent, accumulating multiple substitutions, including T81I, R109S, I115F, R116S, and A119K within the C-terminal region encompassing antigenic domains I-V. B-cell epitope prediction using BepiPred-2.0 identified six epitope patterns (A-F) comprising nine potential B-cell epitope regions (positions 5-19, 33-72, 33-73, 84-85, 87-98, 84-98, 87-97, 84, and 119). Patterns B, E, and F exhibited four to five predicted epitope sites and corresponded to strains 21, 22, 23, and 24. Recombination analysis using RDP v4.101 detected a statistically robust recombination event in strain 18_montana2020-R (lineage 5A), with strain 24_montana2020-WT (lineage 1A) identified as the putative major parent (100% similarity) and the vaccine-like VR2332 strain (lineage 5A) as the minor parent (99.3% similarity). Secondary evidence of the same recombination event was observed in strain 19_montana2020-R. Genetic diversity analysis of the ORF7 gene identified 50 polymorphic nucleotide sites and 52 mutations. Overall, these findings demonstrate substantial genetic variability in the ORF7 gene of PRRSV-2 circulating in Lima, Peru, characterized by lineage co-circulation and inter-lineage recombination. Continuous molecular surveillance is warranted to monitor viral evolution, assess potential antigenic implications, and support effective PRRS control strategies in the Peruvian swine industry.

10
Modelling serological cross-reactivity to disentangle the dynamics of West Nile and Usutu viruses in an emerging area

Bastard, J.; Migne, C.; Helle, T.; Agneray, E.; Bigeard, C.; Boudjadi, Y.; Chevrier, M.; Dumarest, M.; Gondard, M.; Martin-Latil, S.; Mathews-Martin, L.; Petit, T.; Charpentier, T.; Pouillevet, H.; Durand, B.; Metras, R.; Gonzalez, G.

2026-04-17 epidemiology 10.64898/2026.04.07.26350295 medRxiv
Top 0.1%
7.1%
Show abstract

Zoos may serve as sentinel sites for zoonotic vector-borne diseases. West Nile virus (WNV) and Usutu virus (USUV) are closely related orthoflaviviruses transmitted between Culex mosquitoes and a bird reservoir. Both viruses can also infect mammals, including humans, where they may cause symptoms and, more rarely, hospitalization and death. However, serological cross-reactivity between WNV and USUV complicates their differential diagnosis. Here, we aimed to reconstruct the dynamics of emergence of WNV in a zoo located in a newly affected area in Europe, using ELISA and Virus Neutralization Test (VNT) serological analysis of 1707 animal sera collected between 2015 and 2024. Combining this data in a model accounting for cross-reactivity with USUV, we estimated yearly forces of infection (FOI) by both viruses, and thus found that WNV likely circulated in the area one year prior to the first cases reported to the passive surveillance system. Our results also showed that, in the zoo, mammals and reptiles had a lower risk of infection than birds (relative risk of 0.14 [0.05; 0.28]), and that the exposure of birds to water (aquatic lifestyle or proximity to stagnant water) affected the risk. Finally, we estimated diagnosis parameters, including the sensitivity of the VNT (80.4% [76.5%; 84.3%]), the expected VNT titer value, and the level of serological cross-reactivity between viruses during the VNT. To conclude, our modelling framework allowed to disentangle the co-circulation of two closely related viruses, a crucial point in ensuring the reliable sentinel surveillance of these vector-borne zoonotic pathogens.

11
Pathogenesis of H5N1 Clade 2.3.4.4b in dry Jersey cows following intramammary inoculation shows within-host compartmentalization

Cool, K.; Trujillo, J. D.; Kwon, T.; Singh, G.; Kafle, S.; McDowell, C. D.; Fitz, I.; Elango, S.; Lyoo, E.; Vediyappan, G.; Wei, W.; Machkovech, H. M.; Matias Ferreyra, F.; Wilson, W. C.; Cronk, B.; Morozov, I.; Friedrich, T.; Diel, D.; Gaudreault, N. N.; Richt, J. A.

2026-03-04 microbiology 10.64898/2026.03.04.709389 medRxiv
Top 0.1%
6.3%
Show abstract

Dairy cattle have emerged as a prolific amplifying host for highly pathogenic avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b and a new source for cross-species and zoonotic transmission. Independent introductions of H5N1 with unclear exposure routes have been reported in several dairy herds across the U.S. These events escalate the pandemic potential of HPAIV H5N1 as transmission within and between mammalian species present opportunities for mammalian adapted H5N1 viruses to emerge. Although more than 1000 herds have been infected, bovine H5N1 influenza virus pathogenesis, transmission, and evolution in dairy cattle remains not well characterized. Working with H5N1-infected lactating cattle in high containment has been a major challenge due to the required infrastructure and logistics associated with housing, husbandry, and waste management for this model. Thus, developing alternative bovine models that maintain biological relevance while reducing operational complexity is warranted. Here we evaluate the susceptibility of lactating Jersey cattle in the dry-off period and characterize the effect of inoculation dose on the mammary pathogenicity of HPAIV H5N1 genotype B3.13. The results of this study demonstrate that dairy cows 21 days into the dry-off period are highly susceptible to HPAIV H5N1, recapitulating the severe clinical and pathological outcomes observed in infected lactating cows under experimental conditions and in field cases. We also observed an association between virus dose and the onset and severity of mastitis in individual udder-quarters and compartmentalized clonal expansion of variant populations. Overall, this study demonstrates that dry cows can provide a feasible model to study H5N1 virology, pathology, and humoral immunology in dairy cows.

12
Spatial distribution of ticks and tick-borne pathogens in central Hokkaido, Japan and associated ecological factors revealed by intensive short-term survey in 2024

Ito, M.; Ohari, Y.; Kishimoto, M.; Matsuno, K.

2026-02-06 ecology 10.64898/2026.02.03.703647 medRxiv
Top 0.1%
6.2%
Show abstract

Tick-borne pathogens are transmitted by tick bites to cause infectious diseases in humans and domestic animals. To anticipate the occurrence of tick-borne diseases, it is required to understand high resolution distribution of infection risk and associated ecological factors. The aim of the present study is to reveal the spatial distribution of ticks and ticks infected with pathogens in central Hokkaido, Japan. Adult and nymphal ticks were collected with a constant effort at 171 sites from 13 May to 26 June 2024, followed by screening tick-borne pathogens. The potential suitable habitats of seven tick species and the endemic tick-borne pathogens in the study area (i.e. tick-borne encephalitis virus, Yezo virus, Beiji nairovirus, Lyme disease group borreliae, and relapsing fever group borreliae) were predicted using ecological niche modeling. Ixodes persulcatus and Ixodes ovatus were identified as the primary ticks to determine the distributions of all the pathogens. Besides, the predicted suitable habitats were specific to each pathogen/tick species. Among the environmental variables considered for modeling, snow depth appeared to significantly contribute to the distribution differences between ticks and pathogens. The findings of this study expand our understanding of the spatial risk distribution of tick-borne pathogen infections and its ecological context.

13
Clinical and molecular characterization of an outbreak of leptospirosis in dogs from Los Angeles County, California, USA, 2021

Randolph, M. W.; Nally, J. E.; Yoshimoto, S.; Chow, B.; Wagner, D. M.; Stone, N. E.; Sahl, J. W.; Hamond, C.; LeCount, K.; Stuber, T.; van der Linden, H.; Reagan, K. L.; Schrieber, A.; Sebastian, J.; Sykes, J. E.

2026-03-25 microbiology 10.64898/2026.03.24.706307 medRxiv
Top 0.1%
6.1%
Show abstract

BackgroundIn 2021, the Los Angeles County (LAC) Department of Public Health suspected a leptospirosis outbreak in LAC affecting over 200 client-owned dogs. ObjectiveTo characterize the outbreak and describe microbiologic findings, risk factors, diagnostic test performance, and outcomes in dogs diagnosed with leptospirosis at two specialty practices. MethodsLeptospira culture isolates from four cases were subjected to serotyping and whole genome sequencing (WGS); WGS was also performed on one enriched genome isolate. After the outbreak, data were gathered on 59 cases through record review and compared to the background hospital population (controls, n=15,536). ResultsAll isolates were Leptospira interrogans serovar Canicola, but each was distinct based on WGS. Cases clustered in space and in time. Cases evaluated during the outbreak peak had increased odds of exposure to indoor congregate facilities (ICFs). None of 47 dogs with known leptospirosis vaccination history were completely vaccinated. Leptospira real-time PCR on blood and urine and initial serologic testing using the microscopic agglutination test and point-of-care tests were positive in 15/56 (27%), 49/54 (91%) dogs, 22/29 (76%), and 27/35 (77%) dogs respectively. Fifty-four (92%) of 59 dogs survived to discharge; some remained azotemic. No associated human cases were identified. Conclusions and Clinical ImportanceL. interrogans serovar Canicola was associated with a leptospirosis outbreak in unvaccinated dogs from LAC, which had public health implications given widespread dog ownership rates. Data analysis suggested multiple infection sources, including ICFs. Urine PCR was the most sensitive diagnostic test. Such outbreaks might be prevented through more widespread vaccination.

14
Pathogenic Leptospira in dogs and rodents in Tha Wang Pha, Thailand - Prevalence, diversity and linked environments

Jaiwung, W.; Dokhelar, T.; Morand, S.; Chaisiri, K.; De Garine-Wichatitsky, M.; Kritiyakan, A.; Guernier-Cambert, V.

2026-03-20 molecular biology 10.64898/2026.03.16.712015 medRxiv
Top 0.1%
5.2%
Show abstract

Human leptospirosis is a disease of public health importance in Thailand, but the animal species involved in the transmission cycle have not been fully uncovered. This study investigated Leptospira infection in dogs and terrestrial micromammals in rural Nan Province, Thailand, and the pathogen diversity. Sera from 95 seemingly healthy dogs and kidney samples from 399 micromammals were analyzed using real-time PCR for Leptospira detection, followed by conventional PCR and sequencing of infecting Leptospira. We investigated environmental factors associated with Leptospira infection in micromammals, using data collected during trapping. Real-time PCR revealed ongoing infection in 8.4% (8/95) of dogs and 10.0% (40/399) of terrestrial micromammals, with 12 infected species including Bandicota indica, Berylmys berdmorei, Berylmys bowersi, Mus cervicolor, Mus cookii, and Hylomys suillus. In this qPCR-positive micromammals, three pathogenic Leptospira species were identified: L. interrogans, L. weilii, and L. borgpetersenii. This represents the first confirmed detection of L. weilii in rodents in Thailand. Infected micromammals were found in agricultural and forest habitats but not in human settlements. Our study demonstrates potential complex leptospirosis epidemiology in rural Thailand, with multiple species serving as pathogenic Leptospira reservoirs across diverse habitats, and some shared pathogen diversity with human leptospirosis cases in Thailand. Free-roaming dogs may serve as bridge hosts, transmitting zoonotic Leptospira from micromammals to humans by visiting both animal habitats and human settlements. These findings emphasize the need for integrated One Health surveillance approaches to control leptospirosis in rural communities.

15
Mapping high rate clusters of animal contact related human Salmonella enterica single state outbreaks in the United States, 2009 to 2022. A spatial epidemiological approach to inform public health surveillance

Bajwa, H. U. R.; Bhowmick, S.; Varga, C.

2026-04-06 epidemiology 10.64898/2026.04.04.26350168 medRxiv
Top 0.1%
4.4%
Show abstract

Introduction Nontyphoidal Salmonella enterica (NTS) is a major zoonotic enteric pathogen. Animal contact-related NTS outbreaks have increased in the United States of America (U.S.) over the last decade. Geospatial analysis can identify locations with elevated risk of NTS outbreaks where public health authorities can focus their NTS prevention and intervention efforts. Methods We analyzed NTS outbreak data reported from individual states to the Centers for Disease Control via the National Outbreak Reporting System between 2009 and 2022 across the continental contiguous U.S. A geospatial analytical framework that included disease mapping, spatial interpolation, and global and local clustering methods was applied to identify regions with high NTS outbreak rates. Results A total of 104 NTS single-state outbreaks were reported to the National Outbreak Reporting System (NORS) during the study period. The mean annual incidence rate was 0.02 NTS outbreaks per million person-years. The primary animal contact categories associated with these outbreaks were mammals (cattle, pigs, sheep, and horses), birds (backyard chickens, ducklings, and turkeys), and reptiles (turtles and lizards). Exposure settings included farms, fairgrounds, agricultural feed stores, veterinary clinics, dairy/agricultural settings, and residential settings. The local cluster detection methods consistently identified areas with significantly high NTS animal contact-related outbreak rates in the Mountain West, Midwest, and Northeast of the US. Conclusion NTS animal contact-related single-state outbreaks revealed distinct spatial clustering across the United States, with potentially higher risks in the Mountain West, Midwest, and Northeast. Diversity of animal-contact sources and exposure settings depicted complex transmission dynamics of NTS. Focused prevention and control programs in these areas are needed to mitigate the burden of NTS outbreaks.

16
Human enterochromaffin cells and apical-out intestinal organoids as models for human sapovirus infection

Neijd Segerstedt, M.; Nordgren, J.; Hammas, B.; Albert, J.; Svensson, L.; Hagbom, M.

2026-03-08 microbiology 10.64898/2026.03.06.710023 medRxiv
Top 0.1%
4.4%
Show abstract

Human sapovirus is increasingly recognized as a significant cause of acute viral gastroenteritis, but in vitro studies have been limited due to the previous lack of cell models. In this study, we optimized two novel in vitro models for sapovirus infection: the human enteroendocrine cell (EEC) line GOT1 and apical-out 3D human enteroids. Using 31 sapovirus-positive fecal samples, we compared these models with the EEC-derived HuTu80, and human enteroid monolayers, both previously used for sapovirus infection. Among the analyzed samples, genotypes GI.1 (36%), GII.1 (32%), and GII.3 (26%) were identified, with GI.1 exhibiting the highest fecal viral load. We demonstrated that GOT1 cells supported replication of more of the samples containing GI.1 sapovirus (9 of 11) compared to HuTu80 (8 of 11) and with a generally higher replication fold change. Moreover, GOT1 cells were able to support the replication of several GII.1 (3 of 10) and GII.3 (5 of 8) samples, unlike HuTu80 cells that only supported replication of one sample with GII.3 and none of the GII.1 sapoviruses. Given that organoids are considered a more physiologically relevant model than transformed cell lines, we established a sapovirus infection model using human apical-out 3D enteroids. Compared to previously used enteroid monolayers, the apical-out model supported replication of a higher number of samples with GI.1 and with higher replication fold change. In conclusion, these findings provide valuable insights for future in vitro studies of sapovirus infection and replication, which may contribute to a better understanding of sapovirus cell tropism and pathogenesis. ImportanceUnderstanding sapovirus biology requires efficient, reliable, and physiologically relevant in vitro models. By systematically comparing four infection models using clinical samples from three common sapovirus genotypes, this study contributes to important information about differences in cellular susceptibility between these in vitro models. We identified the GOT1 cell line as an efficient model for sapovirus replication and introduced apical-out enteroids as a sensitive organoid-based system for studying sapovirus GI.1. Together, the introduced models provide complementary platforms that can contribute to knowledge about sapovirus pathogenesis and cell tropism as well as provide guidance in selecting suitable in vitro models for future sapovirus research.

17
Pathologies and causes of death in stranded cetaceans in the Canary Islands (2013-2018)

Diaz Santana, P. J.; Arbelo, M.; Diaz-Delgado, J.; Groch, K.; Suarez-Santana, C.; Consoli, F.; Bernaldo de Quiros, Y.; Quesada-Canales, O.; Sierra, E.; Fernandez, A.

2026-04-05 pathology 10.64898/2026.04.01.715953 medRxiv
Top 0.1%
3.9%
Show abstract

Cetacean pathology is a cornerstone for population and marine ecosystem health monitoring, allowing clear differentiation among natural and anthropogenic threats. Previous studies in the Canary Islands reported natural causes of death in 59.4% (1999-2005) and 81% (2006-2012) of stranded cetaceans, versus anthropogenic causes in 33.3% and 19%, respectively. This study aimed to determine the causes of death (CD), pathologic findings, and epidemiological patterns of 316 cetaceans stranded in the Canary Islands between 2013 and 2018. The CDs were classified in pathologic entities (PEs) emphasizing natural versus anthropic origins. Of 316 animals, 224 (70.9%) from 18 species were suitable for pathological investigations. Among natural PEE, natural pathology associated with good nutritional status (NP-GNS) and natural pathology associated with significant loss of nutritional status (NP-LNS) represented 43/224 (19.2%) and 36/224 (16%) cases, respectively. Natural pathology with undetermined nutritional status (NP-UNS) occurred in 19/224 (8.5%) animals. Intra- and interspecific traumatic interactions (ITI) represented 30/224 (13.4%) cases, followed by neonatal/perinatal pathology (NPN) 19/224 (8.5%) and live-stranding stress and/or capture myopathy (LS-CM) 18/224 (8%). Infectious and parasitic diseases predominated in natural PEs. Anthropogenic PEs included interaction with fishing activities (IFA) in 17/224 (7.6%) cases, vessel collisions (VC) in 9/22 (4%) cases, and foreign body-associated pathology (FBAP) in 3/224 (1.3%) animals. Overall, anthropogenic causes accounted for 12.9% of deaths, natural causes for 73.6%, and the CD could not be established in 30/194 (13.4%) cases. This study reaffirms the trends concerning recognized PEs (NP-GNS, NP-LNS, NP-UNS, ITI, NPN, LS-CM, IFA, VC, and FBAP), expands the body of knowledge on cetacean pathology in the Canary Islands, and reports novel findings including mixed infections, clostridiosis in uncommon species, uremic syndrome secondary to urethral nematodiasis, gas embolism in unusual species, epibiont stomatitis, congenital musculo-skeletal malformations, or neoplastic processes. These findings advance understanding of cetacean mortality patterns and support conservation and management strategies.

18
Enhanced Herd-Wide Surveillance Testing Strategy for Porcine Reproductive and Respiratory Syndrome Virus

Barcal, B. M.; DeMers, J. L.; Neujahr, A. C.; Mainquist-Whigham, C. E.; Madigan, J. M.; Bernhard, K. K.

2026-02-03 molecular biology 10.64898/2026.01.26.701801 medRxiv
Top 0.1%
3.7%
Show abstract

ObjectiveThis study aimed to compare a novel surveillance methodology to detect Porcine Reproductive and Respiratory Syndrome virus against oral fluid methodology in swine herds. Materials and methodsTwo pilot studies were conducted using two separate, high-risk commercial nurseries in central Nebraska, comparing two different surveillance sampling approaches (DARO Systems vs. oral fluid (OF)) in the detection of Porcine Reproductive and Respiratory Virus (PRRSV). Each nursery contained eight rooms with an average site inventory of 12,500 pigs. Weekly testing conducted in three of the eight rooms using DARO Systems and OF methodology to identify PRRSV until there was a positive sample, then daily testing of all rooms was conducted. Reverse Transcription-Quantitative Polymerase Chain Reaction was used for identification of positive PRRSV. ResultsSurveillance testing using novel methodology DARO Systems identified PRRSV in nurseries on average 3.91 days earlier than OF. ImplicationsDARO Systems allows for a more robust whole-herd sampling technique to rapidly and accurately detect PRRSV 3.91 days earlier than gold standard approaches. Additionally, DARO Systems allows for an unbiased, whole-herd sampling approach. This method enables producers to implement earlier disease mitigation strategies.

19
Comparison of Three Herd-Level Surveillance Methods for Porcine Reproductive and Respiratory Syndrome Virus

Neujahr, A. C.; Williams, T. E.; DeMers, J. L.; Barcal, B. M.; Peterson, J. S.; Schmitt, C. S.; Bernhard, K. K.

2026-04-01 molecular biology 10.64898/2026.03.31.713744 medRxiv
Top 0.2%
3.7%
Show abstract

This study aimed to evaluate DARO Systems detection of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) against serum and oral fluid surveillance methods within a controlled study consisting of one PRRSV infected seeder pig and 46 naive nursery pigs. Findings showed DARO Systems comprehensive herd-level surveillance approach detected PRRSV earlier than traditional testing methods.

20
Genomic epidemiology of the 2017-2023 outbreak of Mycoplasma bovis sequence type ST21 in New Zealand

French, N. P.; Burroughs, A.; Binney, B.; Bloomfield, S.; Firestone, S. M.; Foxwell, J.; Gias, E.; Sawford, K.; van Andel, M.; Welch, D.; Biggs, P. J.

2026-04-10 genomics 10.64898/2026.04.07.717125 medRxiv
Top 0.2%
3.6%
Show abstract

Mycoplasma bovis was first detected in cattle in New Zealand in 2017, prompting an eradication programme that incorporated extensive surveillance and a test-and-cull policy. Genome sequence data and phylodynamic models were used to inform decision making throughout the eradication programme. Isolates from 697 cattle on 126 farms were collected and sequenced between July 2017 and December 2023. Phylodynamic models were used to estimate the time of most recent common ancestor, the effective reproduction number (Reff) and effective population size, and long-range and local between-farm transmission dynamics. The analysis revealed the dramatic impact of movement restrictions and culling up to early 2020, with a sharp reduction in the Reff to less than 1 in 2018/9 and the extinction of two of three major lineages in 2020. This was followed by three-years of residual infection in farms in the South Island, associated with persistent infection of a large feedlot farm and nearby farms. The comprehensive dataset of genomic and epidemiological data provided a unique opportunity to study the dynamics of a country-wide outbreak of a single-host pathogen from first detection to potential eradication, underlining the utility of integrated genomic surveillance during an outbreak response. Author summaryThe economically important cattle pathogen, Mycoplasma bovis, was first detected in New Zealand in 2017. This led to a large-scale, successful control programme aimed at eradication of the pathogen. The decision to undertake an eradication programme was informed by initial analyses of whole genome sequences from isolates collected as part of the surveillance programme. The analysis showed that the bacteria had entered New Zealand relatively recently and was unlikely to be widespread. Over the subsequent years, genome sequencing and modelling of transmission dynamics informed important policy decisions made by the New Zealand Government and the cattle industry, and helped to monitor progress of the eradication programme. The impact of the detection, movement control and culling programme was profound, with sharp reductions in transmission between 2018 and 2020. This was followed by a long tail of localised infection in the South Island, involving transmission from a large feedlot farm. Provisional eradication was achieved after depopulation of this feedlot. This analysis highlights the role of genomic surveillance and modelling to inform decision making during an infectious disease outbreak.