One Health

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.

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.

Salmonella spp. represents a leading cause of foodborne disease globally. Wild aquatic birds inhabiting ecosystems impacted by human activities may serve as reservoirs and dispersers of Salmonella and antimicrobial resistance genes (ARGs), posing significant public health risks. This study evaluated the prevalence, serovars, resistance genes, and genomic relationships of Salmonella in fecal samples from wild aquatic birds across three high-Andean lakes in Ecuador. Of 134 samples collected from 10 species, five (3.73%) tested positive, all from Yahuarcocha Lake, isolated from Fulica ardesiaca and Phalacrocorax brasilianus. Two serovars were identified: Salmonella Infantis (ST32, n=4) and Salmonella Newport (ST45, n=1). Three S. Infantis isolates exhibited multidrug resistance (MDR), mediated by a pESI-like plasmid carrying resistance genes against beta-lactams, aminoglycosides, tetracyclines, sulfonamides, trimethoprim, fosfomycin, and chloramphenicol. SNP-based phylogenetic analysis revealed low genetic divergence ([≤]10 SNPs) between wildlife and poultry-associated isolates, indicating a shared transmission network. These findings support a likely spillover from poultry production systems into wild bird populations, and highlight the role of wild aquatic birds as ecological sentinels and potential disseminators of MDR Salmonella across interconnected human, animal, and environmental systems. These results underscore the need to incorporate human, animal, and environmental health factors within a One Health framework.

Background. Climate change is intensifying extreme weather events (EWEs) with potentially profound consequences for zoonotic disease dynamics, yet the mechanisms linking EWEs to highly pathogenic avian influenza (HPAI) H5N1 outbreaks remain poorly characterized. The ongoing H5N1 panzootic, responsible for infection in over 500 avian and mammalian species, as well as nearly 1000 human cases and 477 deaths worldwide, provides a critical opportunity to evaluate how climate conditions shape spillover risk at landscape scales. Methods. We compiled a county-month dataset of confirmed H5N1 detections across the contiguous United States from 2022 to 2024 and integrated it with satellite-derived climate metrics, storm event data, and wild bird activity data. We trained and validated a gradient boosting machine classifier to predict outbreak risk and characterize predictor relationships. Results. Our model achieved strong discriminative performance (AUC-ROC = 0.856; AUC-PR = 0.237, representing a 7-fold improvement over chance) and high recall (0.726), supporting its utility as an early warning tool. Human population and temperature-related variables were the most influential predictors: cold temperature shocks and prolonged low temperatures were consistently associated with elevated outbreak risk, likely through enhanced environmental viral persistence, wild bird habitat compression, and allostatic stress-driven immunosuppression in reservoir hosts. Among storm variables, high wind coverage elevated risk, potentially via aerosol dispersal of contaminated particulates, while tornado activity showed an inverse relationship, consistent with documented avoidant behavior in migratory birds. Wild bird reservoir density showed a strong positive monotonic relationship with outbreak risk. Conclusions. Our analyses demonstrate that routinely available environmental and infection data can be used to predict HPAI outbreak risk at fine spatiotemporal scales. These findings demonstrate the divergent roles of short- versus long-term environmental exposures in HPAI spillover dynamics, as well as the potential for machine learning-based surveillance tools to inform targeted biosecurity interventions and early warning systems.

Toxoplasma gondii is a globally prevalent zoonotic parasite with multiple life stages and transmission routes, including ingestion and transplacental transmission. It is a major cause of abortion in sheep, goats and pigs, among other production animals, worldwide. While Type II strains are common in livestock in North America and Europe, non-archetypal, non-clonal genotypes are highly prevalent in South America. This study aimed to determine the molecular epidemiology of T. gondii strains causing sheep abortion in Uruguay. Phylogenomic analyses confirmed significant divergence among typed strains and revealed similarities with genotypes previously detected in the human population. Two novel strains, were isolated and characterized, uncovering the connection between their genetic makeup and phenotypes. Differences in virulence could be correlated to differences in gene copy number of the pseudo kinase ROP5 - further highlighting this virulence factor as relevant in wild strains. Whole-genome sequencing further confirmed the divergence among Uruguayan isolates, uncovering at least three distinct evolutionary origins. Overall, our findings highlight the circulation of virulent non-clonal lineages with links to human infections and underscore the importance of furthering genomic surveillance in South America to better understand Toxoplasmas transmission dynamics, pathogenic potential, and zoonotic risk.

BackgroundAnimal bites represent a significant public health concern due to the risk of injuries and transmission of zoonotic diseases such as Rabies, particularly in low and lower- middle-income countries (LMICs). Understanding the epidemiological characteristics of animal bite incidents is essential for improving the prevention and control strategies. This study aimed to characterize the epidemiological patterns and characteristics of animal bite cases in Sylhet, Bangladesh. Methodology/Principal findingsWe conducted a retrospective analysis of 6,565 animal bite cases reported between January 1 and December 31, 2024, in Sylhet, Bangladesh. Data on demographic characteristics, type of biting animal, site of bite, and exposure category were collected and analyzed to determine associations using correlation analyses and chi-square tests. Among the victims, 3,917 (60%) were male and 2,648 (40%) were female and young adults aged 20-39 years comprised the largest group (39% of cases). The majority of cases (88.1%) originated from urban areas within Sylhet City Corporation. Cats were the leading cause of bites (56.6%), followed by dogs (35.0%) and monkeys (7.5%), suggesting a shift from the traditional dog-dominated pattern. The most frequently affected anatomical sites were the legs (50.3%) and hands (40.9%). Most exposures were classified as World Health Organization (WHO) Category II (98.2%). Bite incidents showed moderate seasonal variation, with peaks in spring and early autumn. A significant declining temporal trend was observed for monkey bites (R = -0.59, p = 0.044), whereas cat and dog bite patterns remained relatively stable throughout the year. Significant associations were identified between bite site and age group, as well as between biting animal and demographic characteristics (p < 0.05). Conclusion/SignificanceThese findings highlight the epidemiological patterns of animal bites in Sylhet and emphasize the need for strengthened public awareness, surveillance, and preventive strategies to reduce animal bite incidents and associated zoonotic disease risks. SynnopsisO_LIA large-scale retrospective analysis of 6,565 animal bite cases revealed a cat-dominant bite pattern (56.6%), contrasting with the traditional dog-dominant paradigm in South Asia. C_LIO_LIYoung adults (20-39 years) and males (60%) were disproportionately affected, reflecting occupational and behavioral exposure risks. C_LIO_LIUrban residents (88.1%) accounted for the majority of cases, highlighting the growing public health burden of animal bites in rapidly urbanizing settings. C_LIO_LIThe most frequently affected anatomical sites were the legs (50.3%) and hands (40.9%). Bite incidents showed moderate seasonal variation, with peaks in spring and early autumn. C_LIO_LICategory II exposures (98.2%) predominated, indicating a high burden of seemingly minor injuries that may be underestimated in rabies prevention strategies. C_LI

Red Mark Syndrome (RMS) is a widespread skin disease affecting rainbow trout (Onchorhynchus mykiss). It provokes substantial economic losses in aquaculture, and is putatively caused by a Rickettsiales bacterium named Midichloria-like organism (RMS-MLO), which is strongly associated with RMS lesions. However, RMS-MLO ecology and epidemiology in aquaculture systems remain poorly understood. In this study, we analysed environmental DNA to monitor the presence of RMS-MLO and its putative vector Ichthyophthirius multifiliis in a trout farm in Northern Italy over one year. Water and sediment samples were monthly collected from multiple water tanks. RMS-MLO was consistently detected by PCR throughout the study in all trout-containing tanks, both in water and sediment samples, but never in the trout-free inflow tank. We did not observe an increase in RMS-MLO abundance during the single RMS outbreak recorded nor in relation with the co-occurrence of I. multifiliis. Our findings indicate a long-term persistence of RMS-MLO in the aquaculture, possibly as a consequence of infections with low prevalence or abundance, rather than its entry from the external environment at the time of RMS outbreaks. Additionally, hints were recorded for a potential role of free-living aquatic microeukaryotes as additional occasional reservoirs. In contrast, I. multifiliis was negatively related with RMS-MLO, while it significantly increased in abundance during the RMS outbreak, particularly in the inflow tank. This supports that, rather than a stable reservoir, I. multifiliis may act as a facilitator of RMS outbreaks, which might indeed be triggered by the entry of this parasite in trout farms.

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.

Research background. Foodborne diseases (FBDs) remain a pressing global public health issue, with courier-based food delivery systems increasingly recognized as potential contamination pathways. In Zambia, despite the Food Safety Act No. 7 of 2019, limited evidence exists on microbial risks in courier-mediated food transport. This study was conducted to assess pathogenic contamination in food carriers used by courier bikers in Lusaka during the 2025/2026 cholera outbreak response. Experimental approach. An analytical cross sectional design was employed. Ninety three food carriers (bags, cooler boxes, and metal containers) were randomly sampled from courier bikers. Swabs from internal surfaces were processed within 24 hours using standard microbiological culture and biochemical identification methods. Statistical analyses (Chi square tests, Pearson correlations, and logistic regression) were applied to determine associations between contamination and operational factors. Results and conclusions. Microbial contamination was detected in 69% of carriers. The most common pathogens were Escherichia coli (30%), coagulase negative Staphylococcus (24%), and Staphylococcus aureus (18%), with additional isolates including Gram-positive bacilli (11%) and Klebsiella pneumoniae (8%). Logistic regression identified cleaning frequency as the strongest predictor of contamination, with infrequent cleaning associated with significantly higher odds ratios (26.5 to 94.7, p < .05). Carrier type also influenced contamination risk, while years in service and certification status were not significant. The findings highlight that inadequate cleaning practices and carrier design are primary drivers of microbiological risks in courier based food delivery systems. Novelty and scientific contribution. This study provides the first empirical evidence of microbial contamination in courier food carriers in Lusaka, Zambia. It underscores the urgent need for strengthened hygiene protocols and routine sanitation enforcement to protect consumers from foodborne pathogens and antimicrobial resistance. The work contributes novel insights into food safety risks in emerging delivery systems, with implications for policy, public health interventions, and consumer protection in Zambia and beyond.

Many studies have identified antibiotic resistant (ABR) Escherichia coli on meat. Appropriate hand hygiene and cooking practices should minimise the risk of gastrointestinal colonisation with ABR E. coli found on meat, and the subsequent chance of causing resistant opportunistic extraintestinal infection. There are large gaps in our understanding of the prevalence, origins and zoonotic potential of ABR E. coli found on meat, however, and particularly for meat reared in extensive farming systems. Wales is a devolved nation within the United Kingdom having large populations of extensively-reared sheep and beef cattle. To help address knowledge gaps around ABR E. coli on extensively reared meat, therefore, beef mince and lamb loin/leg steaks/chops were purchased from 50 (beef) and 46 (lamb) independent butchers across Wales. Following enrichment culture, 200 g meat samples were found to be positive for E. coli resistant to amoxicillin (31% positivity), streptomycin (28%), spectinomycin (29%), amoxicillin-clavulanate (11%), 3rd generation cephalosporins (2%) and fluoroquinolones (5%). Phylogenetic analysis confirmed that Welsh lamb meat ABR E. coli isolates (n=79) are more closely related to those found in faecal samples collected around sheep (n=352) than around beef cattle (n=361) on Welsh farms. This suggests that faecal contamination at or around slaughter is their primary origin. We found no closely related meat/infection clones (<20 SNPs distant and the same antibiotic resistance genes) when comparing ABR E. coli from Welsh meat (n=92) and those causing extraintestinal infections in people (n=2387) in an English region bordering Wales. We conclude, therefore, that the wider zoonotic implications of finding ABR E coli on beef and lamb meat sold at independent butchers in Wales are small.

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.

Soil is an important reservoir for antimicrobial resistance (AMR) and increasingly recognized as a pathogen transmission pathway. While studies have detected AMR in soil in various settings, dominant contributors to domestic soil contamination with antimicrobial-resistant organisms in low-income countries remain unidentified. We conducted a cross-sectional study with 237 households in southern Malawi, specifically peri-urban Bangwe near Blantyre, to identify factors associated with the abundance of cefotaxime-resistant E. coli in yard soil. Enumerators employed structured surveys and sampled 30 cm2 of yard soil per household. We used IDEXX Quanti-Tray/2000 with Colilert-18 and cefotaxime supplement to enumerate the most probable number (MPN) of cefotaxime-resistant E. coli per dry gram of soil. We conducted multivariable regression to assess associations between the abundance of cefotaxime-resistant E. coli and household sanitation, animal ownership and management, child health and antibiotic use, and weather. Of 228 soil samples, 68% harbored cefotaxime-resistant E. coli at a mean of 0.90 log10-MPN/dry gram. Compared to households without animals, households had approximately 0.50-log lower mean cefotaxime-resistant E. coli abundance in soil if animals were enclosed at night and 0.50-log higher abundance if they were not (p-values<0.005). Additionally, samples had approximately 0.70-log lower mean cefotaxime-resistant E. coli abundance if soil was dry at the time of collection and if it came from a household in the top wealth quintile (p-values<0.005). Daytime animal confinement, household sanitation, child health, antibiotic use, rainfall, temperature and ambient humidity were not associated with cefotaxime-resistant E. coli abundance. Findings suggest that animal husbandry and soil moisture had stronger associations with cefotaxime-resistant E. coli in soil compared to sanitation or antibiotic use. These results underscore the importance of a One Health approach and the relevance of domestic animals and environmental factors to AMR in soil. Studies should quantify soilborne AMR exposure and evaluate associations with specific animal management/enclosure practices.

Background: Leptospirosis is a neglected tropical disease with substantial public health impact in Brazil, closely associated with socio-environmental vulnerabilities and climatic extremes. This study analyzed the epidemiological profile, spatiotemporal distribution, and climatic influences on leptospirosis incidence and lethality in Brazil from 2015 to 2024. Methods: An ecological time-series study was conducted using secondary data from the Notifiable Diseases Information System (SINAN). Variables included geographic region, probable infection environment, occupational, and educational level (ISCED-2011). The spatiotemporal correlation between disease incidence and El Nino-Southern Oscillation (ENSO) anomalies was assessed using the Oceanic Nino Index (ONI) and Spearman's rank correlation coefficient. Results: A total of 31,397 cases were notified, with an annual average of 3,140 cases. The South and North regions exhibited the highest incidence rates, while the Northeast and Southeast presented lethality rates above the national average (9.20%). A marked reduction in notifications occurred during the COVID-19 pandemic. Contaminations occurred predominantly in the domiciliary environment (64%). Rural workers (27.45%) and civil construction workers (18.63%) were the most affected occupational groups, with a higher incidence among illiterate and low-education populations. Climatic analysis revealed a positive spatial correlation between El Nino intensification and leptospirosis incidence in the South and Southeast, and a negative correlation in specific Northeastern states. Conclusion: The dynamics of leptospirosis in Brazil are complex and multifactorial, strongly influenced by macroclimatic variations and driven by deficits in basic sanitation and urbanization. Mitigating the disease burden requires sustained, region-specific public health strategies, targeted infrastructure improvements, and enhanced epidemiological surveillance to address underreporting.

Emerging respiratory disease outbreaks pose a major threat to food production systems. Agricultural workers live in larger, more crowded households than the general population, amplifying their potential exposure to respiratory pathogens, yet the consequences for worker health and food production remain poorly understood. We developed a household-structured susceptible-infectious-recovered (SIR) transmission model to compare disease dynamics between agricultural workers and the general U.S. population across six regions. We simulated outbreaks across a range of epidemiological scenarios and assessed productivity losses in California for three labor-intensive crops (oranges, iceberg lettuce, strawberries) with different harvest seasonalities. For a baseline reproduction number of R0 = 1.5, peak disease prevalence among agricultural workers was 1.23-1.45 times higher than that of the general population across regions, and final outbreak sizes were 1.15-1.28 times higher. Peak productivity losses ranged from 0.50%-0.62% across crops, translating to millions in lost revenue. At higher transmissibility and severity (R0 = 3 and assuming all infections are symptomatic), losses were over 2.5 times higher. Household crowding may lead to disproportionate respiratory disease burden among agricultural workers, highlighting the need for targeted outbreak preparedness and mitigation strategies in the agricultural sector to maintain food system resilience and support public health in these communities.

Measurement of antibody responses to viral infection is essential for surveillance, diagnostics, epidemiological research, and natural history of infection studies. However, current methods to detect virus-specific antibodies are often resource-intensive and impractical for deployment in outbreak settings or in field-based studies. This manuscript presents two economical, high-throughput immunoassays--the cytoblot immunoassay (CBA) and strip immunoblot assay (SIA)--for detecting and quantifying anti-lymphocytic choriomeningitis mammarenavirus (LCMV) antibodies in mouse serum. To validate, we tested serum from acutely or persistently experimentally infected mice. Both assays detected LCMV-specific IgG and IgM antibodies with high sensitivity and specificity across multiple timepoints. By facilitating the study of immune responses in rodent reservoirs, these tools can enhance our understanding of zoonotic viral transmission, provide scalable platforms for outbreak preparedness, and serve as adaptable models for the development of rapid serological assays for other viral pathogens.

BackgroundHuman-Wildlife Conflict is emerging as one of the most critical conservation and socio-economic challenges in the Ecuadorian Andes, where both rural livelihoods and native fauna are under increasing pressure. Small-scale livestock producers in the region depend almost entirely on a limited number of cattle, meaning that the loss of even a single animal can lead to severe economic hardship. In response, antagonistic actions against wildlife are frequent, further threatening vulnerable species. At the same time, the recent proliferation of feral dogs adds a new dimension to conflict, posing risks to both livestock and native fauna. Despite the growing severity of this conflict, little is known of its drivers, spatial patterns, and socio-ecological consequences. This study seeks to fill that gap by generating insights to inform targeted conservation strategies for community-based mitigation of conflict with spectacled bears and feral dogs. MethodsTo assess the drivers and dynamics of HWC in southern Ecuador, we conducted structured interviews with livestock owners, quantifying the frequency and intensity of conflicts across multiple species and evaluating whether farm composition and management practices predict conflict patterns. ResultsOur results reveal that large carnivores cause significantly higher economic losses than smaller predators; furthermore, feral dogs have emerged as the primary source of financial damage over the past five years. Farms with a greater proportion of forest edge were associated with a higher probability of severe conflict, particularly with large carnivores. ConclusionsThese findings underscore the urgent need for proactive strategies to promote coexistence. Identifying predictive variables of conflict risk is crucial for vulnerability assessments and the design of effective mitigation policies. Controlling feral dog populations is likely to be a critical step in safeguarding both rural human livelihoods and native biodiversity in the Andean landscape.

BackgroundWorking equids are fundamental to the socioeconomic structure of Mexicos small-scale agricultural sector, which accounts for 71.2% of the countrys active Agricultural Production Units (APUs). Despite their critical role in human rural livelihoods, food security, and sustainable development, these animals face systemic "statistical invisibility" within national and international productive frameworks. This study evaluates the long-term population dynamics and geographical distribution of working equids to analyze their current status amidst agricultural modernization. MethodsA retrospective analysis was conducted using national census data from 1970 to 2022 provided by the National Institute of Statistics, Geography, and Informatics (INEGI). Population trends for horses, donkeys, and mules were calculated using the Average Annual Variation Rate (AAVR). The severity of population declines was classified according to an adaptation of the International Union for Conservation of Nature (IUCN) criteria. Finally, national census records from INEGI, Agri-food and Fisheries Information Service (SIAP) and The Ministry of Agriculture and Rural Development (SADER) were contrasted with FAOSTAT database estimates to identify reporting discrepancies. ResultsBetween 1970 and 2022, the total equine population in Mexico decreased by 76.5%, falling from 6.8 to 1.6 million. However, a "paradox of modernization" was identified: while total numbers plummeted, the proportion of equids used specifically for work reached a historical peak of 81% in 2022, effectively having doubled from the 44% recorded in 2007. While donkeys and mules have suffered drastic total reductions (87% and 88%, respectively), working horses experienced a resilient 37% recovery between 2007 and 2022 (+3.71% AAVR). Furthermore, a staggering 710.8% discrepancy was found between national census data and FAOSTAT estimates, representing an overestimation of 11.3 million animals in international records. ConclusionsThe persistence and recent recovery of working equids reflect a "resilience of necessity" for approximately 500,000 APUs that depend exclusively on animal traction and packing due to economic constraints and complex topography. These findings challenge the narrative of total agricultural mechanization and highlight an urgent need for evidence-based public policies that address the statistical invisibility of working equids as indispensable drivers of rural sustainability and food security.

This novel study detected persistent low level infections of Elephant Endotheliotropic Herpesviruses (EEHV), that can cause highly pathogenic Elephant Hemorrhagic Disease (EHD) in Loxodonta and Elephas, and co-infection of presumed less pathogenic Elephant Gammaherpesviruses (EGHV), in skin nodule biopsies, saliva and tissues collected from 43 wild L. africana (savannah elephant) in Botswana, Kenya, South Africa and Zimbabwe; in saliva from 25 wild L. cyclotis (forest elephant) in Gabon; and in saliva collected over seven years from 7 wild-born L.africana at Six Flags Safari Park, USA; and in saliva, blood and tissues from an additional 200 L. africana in USA zoos. DNA from these samples was extracted in our USA laboratories and amplified by conventional polymerase chain reaction using three-round nested primer sets designed specifically to screen for known EEHV and EGHV genes loci and to discover new species and subtypes. Sanger sequencing of purified DNA from nearly all samples yielded unambiguous positive genetic matches to previously known Loxodonta-associated EEHV2, EEHV3A, EEHV3B, EEHV6, EEHV7A, and EGHV1B, EGHV2, EGHV3B, EGHV4B, EGHV5B and discovered novel types EEHV3C-H and EEHV7B and the prototype EGHV1B. Many of the primer sets used could also have detected known Elephas-associated EEHV1A, EEHV1B, EEHV4, and EEHV5 if present in these samples, but they did not. Our extensive library of EEHV and EGHV sequences from wild and zoo Loxodonta, (as well as from 100 zoo Elephas maximus not discussed in this review), is a significant contribution to the elephant virology community, particularly for comparing subtypes types of EEHV found in pathogenic cases of EHD in zoos as well as determining and comparing species and subtypes of EEHV present in existing zoo herds, and in individual elephants being transported between zoos, and for importation of wild elephants into existing zoo herds.

Despite significant reductions in malaria cases across Brazil, residual transmission persists in the Legal Amazon, threatening the national goal of elimination by 2035. The Amazonian socio-ecological landscape creates a complex environment where environmental degradation and socioeconomic vulnerabilities intersect. However, the independent and combined effects of these drivers remain poorly quantified at a regional scale. We conducted a retrospective, longitudinal ecological study analyzing a comprehensive panel dataset from 2021 to 2025 across all 773 municipalities in the Brazilian Legal Amazon. We evaluated the independent effects of prior-year deforestation, extreme poverty, population density, fire activity, macroclimatic variables, and primate reservoir abundance on malaria incidence. Deforestation emerged as the dominant predictor of malaria intensity. A one-standard-deviation increase in lagged deforestation area was associated with a 48.3% increase in expected malaria cases. Socioeconomic deprivation also significantly sustained transmission, with extreme poverty increasing cases by 18.8%. Conversely, population density exhibited a strong protective effect, reducing incidence by 72.2%, reflecting the phenomenon of urban protection. While an overall temporal decline of 17.4% annually was observed, profound spatial heterogeneity persisted, with the state of Amazonas maintaining consistently high transmission without a discernible downward trend. Macroclimatic factors and primate abundance did not show statistically significant independent effects at the annual municipal scale. The persistence of malaria in the Brazilian Amazon is not merely a biomedical issue but a profound sustainable development challenge driven by the synergistic effects of land-use change and socioeconomic inequality. Deforestation and extreme poverty create a resilient reservoir of transmission risk that undermines conventional control efforts. Achieving the 2035 elimination goal demands a paradigm shift toward a One Health approach, integrating rigorous environmental protection, targeted social development, and spatially stratified public health interventions. Ultimately, the health of the Amazonian population is inextricably linked to the health of the forest itself.

The emergence of the panzootic clade of highly pathogenic avian influenza H5N1 (2.3.4.4b) in 2020 marked a major expansion in the host range of influenza A viruses (IAVs), raising concerns about further cross-species transmission events and zoonotic spillover. Introduction of 2.3.4.4b viruses into U.S. dairy herds has resulted in widespread circulation, accompanied by reduced milk yield, mastitis, and high viral loads in milk. Notably, virus circulation in dairy cattle represents a novel route for mammalian adaptation and transmission that has already led to more than 40 human cases in the U.S. since 2024. Here, we investigated whether avian clade 2.3.4.4b viruses could infect mammary tissue from Aberdeen Angus, Holstein Friesian, and Limousin cattle, three breeds commonly farmed in Europe, the Americas, and Oceania. Using mammary gland explants, we inoculated tissues with attenuated reassortant viruses expressing the haemagglutinin and neuraminidase glycoproteins of three 2.3.4.4b viruses that predated the emergence of H5N1 in US cattle: A/chicken/England/053052/2021 (AIV07), A/chicken/Scotland/054477/2021 (AIV09), and A/chicken/England/085598/2022 (AIV48). Infected epithelial cells were identified using immunohistochemistry in explants from both the teat and gland cistern for all three breeds following infection with AIV09 and AIV48, indicating that mammary tissue from each of the three tested cattle breeds cattle is permissive to H5N1 infection. Lectin staining showed expression of both 2,3-linked and 2,6-linked sialic acids in the mammary tissue of all donors showing that all three breeds have the potential to support infection with both avian-adapted and mammalian adapted IAVs. Together, these findings demonstrate that mammary glands from both beef and dairy cattle breeds are permissive to infection with avian-adapted and mammalian-adapted H5N1 viruses and highlight the potential for this tissue to act as a mixing vessel for IAV reassortment, underscoring the need to include cattle in ongoing H5N1 surveillance and risk-assessment frameworks. Impact StatementThe emergence of highly pathogenic avian influenza H5N1 in dairy cattle has expanded the recognised host range of influenza A viruses. Further, the ability of the virus to infect the mammary gland and transmit via milk revealed a novel interface for transmission to humans and animals. Although sustained circulation in US dairy herds has been reported, the susceptibility of mammary tissue from other breeds (including beef cattle) commonly used in different countries has been largely unexplored. Here, we show that avian-origin H5N1 viruses can infect tissues derived from the mammary gland of three common cattle breeds (Aberdeen Angus, Holstein Friesian, and Limousin). Virus was detected in epithelial cells from both dairy and beef breeds, indicating that H5N1 can infect multiple breeds. Receptor profiling showed abundant 2,3-linked and 2,6-linked sialic acids, consistent with a tissue environment that may support infection with both avian-adapted and mammalian-adapted viruses. These findings demonstrate that multiple cattle breeds are permissive to H5N1 infection and strengthens the evidence base for including cattle in H5N1 surveillance and risk-assessment frameworks.