Transboundary and Emerging Diseases

Highly pathogenic avian influenza (HPAI) viruses from clade 2.3.4.4 have caused recurrent outbreaks in poultry since 2014. In the Republic of Korea, clade 2.3.4.4b viruses have driven five epidemic waves, yet the factors underlying HPAI introduction and farm-to-farm spread remain poorly understood. We compiled hemagglutinin gene sequences of clade 2.3.4.4b viruses from wild birds and poultry in the Republic of Korea (October 2016-March 2024) and reconstructed dispersal dynamics using Bayesian phylogeography. Dispersal patterns suggest that domestic duck farms in the western provinces likely form a key interface for spillover from wild birds into poultry. Mixed-effects generalized linear models showed that both wild-to-poultry and farm-to-farm transition rates were positively associated with the number of poultry farms in the destination province, while wild-to-poultry rates were further associated with higher avian influenza virus infection probability among wild birds. Wild-to-poultry transition rates were lower in 2020-2024 than in 2016-2018, which may reflect strengthened interventions. These findings suggest that poultry farm abundance and introduction pressure from wild birds jointly shape the spatial dynamics of HPAI introduction and spread. More broadly, these factors may provide operational indicators to guide risk-based surveillance and control strategies. Author SummaryHighly pathogenic avian influenza (HPAI) H5 viruses continue to cause major losses in poultry and pose recurring risks at the wildlife-livestock interface. Effective control depends on identifying where viruses are most likely to enter poultry populations and how they spread between farms. Using viral genomic data from wild birds and poultry in the Republic of Korea, this study suggests that domestic duck farms in western provinces likely form a key interface for introductions from wild birds into poultry. We also found that regions with more poultry farms were more likely to receive and spread the virus, while introduction risk was further elevated where infection pressure from wild birds was higher. By linking viral genomic patterns with ecological and epidemiological information, our study helps identify where HPAI viruses are most likely to enter poultry populations and spread between farms. These findings can guide targeted surveillance and early control in regions at greatest risk.

A parvovirus recently associated with an outbreak in Dutch pigs was found in Denmark in symptomatic pigs and in fox (Vulpes vulpes) feces and spleens. Pig viruses were more closely related to each other than to viruses found in the respective local wildlife, suggesting a link between the farm outbreaks.

Influenza A virus (IAV) circulates widely in European pig populations and continues to diversify through frequent introductions from humans, followed by reassortment within swine. Spain represents a particularly dynamic ecological setting due to the coexistence of intensive whitepig production, extensive Iberianpig systems, and abundant wild boar populations. This study provides an integrated analysis of IAV evolution and genomic diversity in swine in Spain between 2019 and 2022, expanding on previous surveillance from 2016 to 2019. Sampling across 24 provinces yielded 66 new wholegenome sequences from Iberian and white pigs. We identified 18 genotypes, including 11 novel reassortants not detected in our previous survey. Several genotypes, such as H1huN2 G21 and G22, H3N2 G23, and the unusual H3N1 G12, were exclusive to the country. Some genotypes were detected across white pigs, Iberian pigs, and wild boar in Toledo and Badajoz, suggesting viral flow among swine populations. Phylogenetic analyses revealed ongoing introductions of H1N1pdm09 from humans into pigs, generating at least five reassortant genotypes (G10, G16-G19). These lineages incorporated pandemic internal cassettes and, in some cases, humanseasonal N2 segments, highlighting the continued role of humans as a source of viral incursions. Conversely, four zoonotic infections (H1N1v) detected in Spain between 2022 and 2026 were linked to genotypes circulating in white pigs, underscoring the bidirectional nature of IAV transmission at the human swine interface. Overall, this study demonstrates that Spain provides ecological conditions conducive to IAV diversification, reassortment, and zoonotic risk. The findings reinforce the need for sustained One Health surveillance. HighlightsO_LINovel swine influenza virus (SIV) genotypes exclusive to Spain C_LIO_LIPhylogenetic analysis of genomic segments of zoonotic variants of swine origin detected in Spain since 2022 C_LIO_LIShared circulation of influenza A compatible with interbreed transmission among domestic pigs and wild boar C_LI

Coronaviruses of the genus Gammacoronavirus cause major poultry diseases, including infectious bronchitis in chickens and enteritis in turkeys and guinea fowl. Until now, no enteric coronavirus distinct from infectious bronchitis virus had been reported in chickens. Between late 2024 and 2025, severe enteritis outbreaks affected broiler farms in southwestern France, causing increased mortality, wet litter, cyanosis, lethargy, ruffled feathers, and high slaughter condemnation rates. Necropsy and histopathology revealed diffuse enteritis and dehydration. Metagenomic sequencing identified abundant coronavirus reads as the only pathogenic viral signal. Whole-genome phylogeny showed a novel gammacoronavirus lineage closely related to guinea fowl coronavirus but distinct from infectious bronchitis virus and turkey coronavirus. Viral RNA was detected in enterocytes by RNAscope in situ hybridization, and electron microscopy revealed coronavirus-like particles. These findings describe a novel enteritis-associated coronavirus in broiler chickens (ChECoV), although the drivers of its host-range expansion into chickens remain to be elucidated.

Johnes disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), is an important livestock disease in Japan. We typed 48 field isolates from cattle feces collected on 13 farms in Kushiro Subprefecture during 2024-2025 and 62 MAP-positive cattle fecal samples collected in the same region during 2025-2026 using a real-time PCR assay targeting the Type S-specific arylsulfatase gene. No Type S strains were detected among the cultured isolates or fecal samples examined in this study, suggesting that the cattle cases analyzed were more consistent with Type C than with Type S strains. Broader surveys are needed to define MAP strain diversity in Japan and improve control strategies.

Avian influenza viruses (AIVs) are endemic in the Americas and responsible for outbreaks in both domestic and wild birds that occasionally spill over into humans. We report the first known outbreak of AIV H9N2 in lesser rhea (Rhea pennata), also known as Darwins rhea, in the region of Puno-Peru. The animals in this study lived in an isolated conservation center located in remote highlands above 4,000 m.a.s.l. Between June and July 2025, a total of 46/92 animals were recorded sick, with symptoms including greenish diarrhea (100%), hyporexia (24%), dyspnea (76%), nasal discharge (42%), drowsiness (18%) and isolation from the flock (73%), and 94% later died. Gross pathology exams revealed septicemia characterized by severe hepatitis, pneumonia, tracheitis, enteritis, and encephalitis. Swab and necropsy samples tested positive for Influenza A by PCR and were later identified as H9N2 through whole genome sequencing. We generated complete H9N2 genomes for two individuals. No additional pathogens were found. Phylogenetic analysis across all eight segments revealed that the viruses were low pathogenicity H9N2 AIV strains of North American origin, which indicated this outbreak was a new introduction of the virus into South America. We also performed a comparative mutational analysis and identified multiple mutations previously associated with mammalian host adaptation, increased virulence, increased pathogenicity, and increased virus binding to 2-6 receptors, which may explain the high mortality rates observed despite the supposedly low pathogenicity of the strain. We also identified novel mutations specific to rhea viruses that will need to be experimentally validated. This is the first report of a natural H9N2 systemic infection in an avian host, highlighting a need for increased surveillance efforts for zoonotic influenza viruses with pandemic potential. Author SummaryAvian influenza viruses (AIVs) are endemic in the Americas and cause more than 7,600 infections annually in domestic and wild birds worldwide each year. We report detection of AIV H9N2 in lesser rhea during an outbreak that occurred in June-July 2025 in the Andean highlands of Puno in Peru. Multiple sick animals were reported with symptoms of respiratory and gastrointestinal disease and 94% of them later died. Samples collected tested positive for Influenza A and they were subtyped as H9N2 of low pathogenic origin from North America. This is the third time H9N2 enters South America from North America, presumably through wild birds, some of which migrate along the Pacific Flyway. Comparison with other H9N2 sequences revealed a total of 44 mutations of interest that may explain the elevated death rates observed. Surveillance in wild birds remains patchy at best and needs to be strengthened in order to prevent spillover events into other animals, including humans.

Alongshan virus (ALSV) is an emerging tick-borne segmented RNA virus belonging to the Jingmenvirus group and has been reported in humans, ticks, and vertebrates across Asia and Europe. Despite its potential public health relevance, its distribution and genetic diversity remain poorly characterized in several European regions where tick-borne pathogens are endemic. In this study, we developed a specific TaqMan-based real-time RT-PCR assay targeting a conserved region of ALSV segment 2 and used it to investigate the presence of ALSV RNA in Ixodes ricinus ticks collected in northeastern Italy. The assay showed high linearity over a broad dynamic range and no cross-reactivity with related flaviviruses. A total of 212 archival tick samples collected between March 2021 and November 2022 were screened, and 28 samples (13.2%) tested positive for ALSV RNA. Positive ticks were detected in the provinces of Belluno and Vicenza and included individual adult males and nymph pools. A subset of positive samples was further characterized by nested PCR and Sanger sequencing of all four genomic segments. Phylogenetic analyses showed that Italian ALSV sequences clustered within the broader European ALSV diversity and were closely related to strains from Central and Northern Europe, without forming a distinct country-specific lineage. Sequence comparisons suggested purifying selection and revealed differences in predicted structural proteins between European and Chinese strains. These findings provide the first molecular evidence of ALSV circulation in Italy and support further studies to clarify its epidemiology, host range, genetic diversity, and potential clinical relevance. IMPORTANCEAlongshan virus (ALSV) is an emerging tick-borne virus identified in febrile patients in China and subsequently detected in ticks in Russian Federation and several European countries. Although severe disease has not yet been reported in humans, surveillance and elucidation of the virus distribution are essential to assess its pathogenicity and potential public health impact. We developed a specific real-time RT-PCR protocol and detected ALSV in Ixodes ricinus ticks collected in northeastern Italy. Sequence analyses suggested multiple introductions and revealed differences in structural proteins between European and Chinese strains, suggesting potential adaptation and differences in pathogenicity. Since the clinical signs of ALSV infection in humans may overlap with those of tick-borne encephalitis (TBE), differential diagnostic procedures should be developed to improve patient management, particularly in TBE-endemic regions such as northeastern of Italy.

Background Brucellosis is a severe zoonotic disease with pronounced seasonality and regional heterogeneity in high-incidence areas of China. Reliable forecasting tools are needed to inform prevention strategies, but the optimal modeling approach across different regions remains unclear. Principal Findings We collected monthly brucellosis incidence and 17 environmental variables from 2014 to 2024 across five high-incidence provinces: Inner Mongolia, Xinjiang, Shanxi, Heilongjiang, and Hebei. A three-step procedure--cross-correlation analysis, multicollinearity diagnostics, and stepwise regression--was used to select exogenous predictors. We then compared four time-series models: seasonal autoregressive integrated moving average (SARIMA), SARIMA with exogenous variables (SARIMAX), long short-term memory (LSTM), and LSTM with exogenous variables (LSTMX). All five provinces showed a unimodal seasonal pattern with peaks between April and July, though environmental drivers and optimal lag periods varied substantially by region, ranging from 1 to 6 months. In forecasting performance, LSTM achieved the highest accuracy in Shanxi (R2=0.925), Hebei (R2=0.876), and Xinjiang (R2=0.829), outperforming SARIMA and SARIMAX. LSTMX performed best in Inner Mongolia (R2=0.759) and Heilongjiang (R2=0.772) but showed weaker performance than LSTM in Shanxi and Hebei. Overall, adding exogenous variables did not consistently improve predictions across provinces. Conclusions Our findings demonstrate that LSTM-based models offer clear advantages for brucellosis forecasting in most high-incidence provinces, but the value of incorporating environmental predictors is region-dependent. These results support the development of tailored early warning systems and precision prevention strategies for brucellosis in high-risk areas of China.

Background: Q fever, caused by Coxiella burnetii, is a zoonosis with significant public health implications. Spain has the highest number of cases in the European Union/European Economic Area, but the clinical and hospitalization burdens remain poorly characterized. This study described the epidemiology, demographic and clinical characteristics, and geographical distribution of hospitalized Q fever patients in Spain from 2016 to 2023. Methods: We conducted a nationwide, retrospective study using the Spanish Minimum Basic Data Set for Hospitalization (MBDS-H). All hospital admissions with an ICD-10-CM code for Q fever (A78) between 2016 and 2023 were included. We analyzed demographic data, comorbidities, complications, length of stay, intensive care unit (ICU) admission, and mortality. We calculated hospitalization rates per 100,000 population. Temporal trends were assessed using Poisson regression. Results: We identified 3,358 hospitalizations for Q fever, representing an overall hospitalization rate of 0.89 per 100,000 population. The median patient age was 56 years (interquartile range [IQR] 42-70), and the cohort was predominantly male (72%). The median hospital length of stay was 9 days (IQR 6-15), and 8.3% required ICU admission. The overall mortality rate was 2.4%. The most common complication was pneumonia (32%). Significant upward trends were observed over the study period for patient age, hypertension, and acute heart failure (p<0.05). Geographical analysis revealed the highest hospitalization rates in the Canary Islands (2.33), La Rioja (2.16), and the Balearic Islands (1.93). Conclusion: This study highlights the hospitalization burden due to Q fever in Spain. The risk of hospitalization increases with age and the presence of predisposing conditions. The marked regional heterogeneity and high frequency of complications such as pneumonia underscore the need for enhanced surveillance and a strengthened One Health approach to control this zoonosis.

Lumpy skin disease (LSD) is an emerging cattle disease caused by lumpy skin disease virus (LSDV), with major impacts on the industry, being classified as a Category A disease. Although it was historically confined to Africa, LSD has expanded into the Middle East, Asia and Europe. Here, we report two LSDV genomes from the first outbreak detected in Catalonia, Spain, in October 2025. The genomes were assembled from high-throughput sequencing data generated from two homogenized skin nodules. Comparative phylogenetic analyses were performed using all available complete LSDV genomes and rpo30 gene sequences. These analyses placed the LSDV isolates detected in Catalonia within clade 1.2, closely related to the isolates recently reported in Sardinia, Italy. Our findings also support a connection between recent south-western Europe and central African strains, possibly through northern Africa, and highlight the need for more complete genomes to clarify the origin and connections among recent LSDV outbreaks.

Infections at the animal-human or wildlife-livestock interfaces have severe health and socio-economic consequences. Combined with empirical data, mathematical models can contribute to a better understanding of the reservoirs of these infections, which is a priority for mitigating their impact by using appropriate management interventions. Taking brucellosis in the Bargy massif (French Alps) as an example of a zoonosis at the wildlife-livestock interface, we developed and calibrated a multi-host model integrating data on direct and environment-mediated cross-species contacts from field observations. Estimates of the basic reproduction number (R0) allowed to identify the population of Alpine ibex (Capra ibex) and its environment as an essential host in the reservoir, driving both pathogen maintenance (within-species R0[&ge;]1: 1.66, 95% credible interval: 1.42-2.03) and its transmission to livestock (between-species R0>0: 0.035, 0.01-0.05). Our approach can be adapted to other multi-host pathogens, which will contribute to improve the understanding and management of these complex systems.

Global efforts to prevent and mitigate the impacts of high pathogenicity avian influenza (HPAI) H5 on domestic animals, humans, and wildlife rely on timely and transparent information that is both accurate and interpretable across countries and sectors. International epidemiological and genomic databases, such as the World Animal Health Information System (WAHIS), the Global Animal Disease Information System (EMPRES-i+), the Global Initiative on Sharing All Influenza Data (GISAID), and the National Center for Technological Bioinformation Virus Portal (NCBI) provide essential information for surveillance, research, and decision-making. To evaluate how well these resources capture recent wildlife impacts, we consolidated information from these databases and complementary public sources including government reports, scientific literature, and news articles, on wildlife mortality associated with HPAI H5 in the Americas from November 2021 to July 2024. The consolidated dataset comprised 615,883 wild birds (287 spp.) and 63,409 wild mammals (39 spp.). In comparison, WAHIS represented 16,902 wild birds (261 spp.) and 6,323 wild mammals (31 spp.) while EMPRES-i+ captured a substantially smaller portion of affected host diversity for both wild birds (105 spp.) and wild mammals (27 spp.). Genomic databases (GISAID and NCBI) represented 7,027 whole genome equivalents of H5 viruses from wild birds (175 spp.) and 371 from wild mammals (26 spp.). These discrepancies indicate that international databases, while essential, provide an incomplete picture of HPAI impacts on wildlife, with significant geographic and taxonomic asymmetries attributable to differences in surveillance capacity, reporting practices, sequencing effort, and data-sharing pathways. Studies and management strategies relying on these resources without complementary validation may therefore mistake data gaps for real-world epidemiological patterns. Strengthening data reporting standards, improving validation procedures, and integrating international databases with national reports, scientific publications, and other sources will enhance the reliability of epidemiological analyses and support more effective One Health surveillance, risk assessment, and conservation action. Author summaryHigh pathogenicity avian influenza (HPAI) H5 viruses, often called bird flu viruses, can cause severe disease in birds and mammals, including humans. Because of their relevance for human health, livestock production, and wildlife conservation, international databases were established to share information on when and where these viruses are detected, which species are affected, and what virus strains are found. These databases are essential tools for governments, scientists, and conservation practitioners working to track outbreaks, understand how these viruses spread and evolve, and guide surveillance and response. In this study, we compiled and compared information on recent HPAI H5 events in wildlife in the Americas available in international databases with information from other public sources, including reports from governments, scientific literature, and news articles. We found important discrepancies in how countries and species affected were represented across sources. As a result, international databases might not fully capture the actual distribution or conservation impact of HPAI H5 on wildlife. Our findings also show why decision-makers and scientists should interpret database-derived patterns carefully. We provide recommendations to improve international databases to address these gaps and better inform One Health risk assessment and wildlife conservation actions.

BackgroundLyme borreliosis is a common tick-borne disease in Europe caused by spirochetes of the Borrelia burgdorferi sensu lato complex, including Borrelia afzelii, which is maintained in nature through interactions with rodent reservoir hosts. These spirochetes have evolved several surface proteins to manipulate rodent host immunity, some of which remain polymorphic in Borrelia populations. Among these proteins, OspE, which binds the host complement-regulating factor CFH to evade destruction by complement, is one of the most variable. Yet, what evolutionary forces maintain this polymorphism is not well understood. Motivated by a recent discovery of CFH polymorphism in the bank vole (Clethrionomys glareolus), the main reservoir host of B. afzelii, we hypothesized that the polymorphism is maintained by host-parasite coevolution involving specific associations between host and parasite genetic variants. MethodsWe analyzed associations between bank vole CFH alleles and B. afzelii OspE variants across three datasets sampled in Poland. Selection acting on OspE was evaluated using omegaMap. Host-pathogen genotype associations were tested using partial redundancy analysis (RDA), and co-structure was assessed using co-correspondence analysis (CoCA). ResultsWe found that OspE evolves under positive selection, however, we found no evidence for an association between OspE and host CFH variants at the individual level based on RDA or at the population level based on CoCA. ConclusionsDespite evidence of positive selection acting on OspE, we found no support for specific genetic matching between B. afzelii and its bank vole host at the CFH-OspE interface. These results suggest that the evolution of CFH and OspE may be shaped by broader selective pressures, potentially including interactions with multiple host species.

Introduction: Hantavirus disease is an emerging and potentially severe zoonosis of global distribution. In Uruguay, it is transmitted by rodents inhabiting peridomestic, suburban, and rural areas. Global incidence is estimated at 150,000 to 200,000 cases per year, with up to 300 annual cases in the Americas. Since 1997, Uruguay's Ministry of Public Health (MPH) has monitored Hantavirus cardiopulmonary syndrome (HCPS), the most common clinical presentation in the region. By 2019, a total of 271 cases had been identified in the country, with an estimated mortality rate of nearly 50%. Objectives: To describe the clinical, epidemiological, and occupational characteristics of patients with Hantavirus disease in Uruguay during the pre-pandemic (2018-2019) and pandemic (2020-2021) periods. Methods: A descriptive, cross-sectional, observational study was conducted, including all serologically confirmed cases of Hantavirus infection reported to the MPH between 2018 and 2021. Clinical and demographic data were extracted from the mandatory reporting form for zoonotic diseases. Incidence and case fatality rates were calculated, and factors associated with fatal outcomes were analyzed. Results: A total of 58 confirmed cases were identified between 2018 and 2021. Most patients were male (62%), with a mean age of 36.5 years (SD 16). A decline in incidence was observed during 2020-2021, with no significant change in case fatality. Direct rodent exposure was the most frequently associated risk factor. Montevideo and Canelones were the most affected departments. Renal and pulmonary involvement were significantly associated with mortality. Conclusion: Hantavirus remains a relevant public health concern in Uruguay. Although a decrease in incidence was observed during the COVID-19 pandemic years, case fatality rates remained high. The findings underscore the need for sustained surveillance and early recognition, particularly in urbanizing regions.

Rickettsia senegalensis is a novel Rickettsia species isolated from cat fleas, Ctenocephalides felis, in Senegal. Genomic analysis confirmed its status as a distinct species, placing it within the transitional Rickettsia group, within a R. felis cluster. Furthermore, rickettsial genes identical to those of Rickettsia senegalensis had been already identified in several hematophagous arthropods, including fleas and ticks parasitizing various hosts such as cats, dogs, opossums, and rodents in tropical and subtropical regions all over the world. It has also been detected in cat tissues, suggesting a potential host-pathogen association. Here we formally propose Rickettsia senegalensis sp. nov. as a new species. The type strain of this species is strain PU01-02T (= CSUR R184T = DSM 28250T). Strain PU01-02T grows aerobically in XTC-2, SF9, and LD652 cell lines at 28 {degrees}C in a CO2-free atmosphere. The genome of strain PU01-02T has a size of 1.62 Mb and a G+C content of 33.2%. RepositoriesThe genome sequence of Rickettsia senegalensis sp. nov. strain PU01-02T has been deposited in GenBank under accession number JBVYTQ000000000, and the rrs, gltA, ompB and sca4 gene sequences under accession numbers KF666476, KF666472, KF666470, KF666474, respectively. The plasmid accession numbers are PZ272915, PZ272916, and PZ272917, for pRS01, pRS02 and pRS03, respectively.

Mycoplasma bovis is a minimal bacterium infecting cattle, which causes a wide variety of symptoms and is impacting dairy and beef producers worldwide. Part of the difficulty in research surrounding M. bovis, and other mycoplasmas, is the lack of efficient genome editing tools. As a proof of concept, we previously presented a transposon-based CRISPR-Base Editor system to introduce targeted mutations in M. bovis. In this work, the existing tool has been greatly improved: multi-loci targeting through addition of a second guide RNA; increased number of targetable loci by using an engineered Cas9 with AT-rich PAM specificity, and elimination of the CRISPR-Base Editor from the generated mutants through either transposon excision or use of a curable plasmid. We also propose a dedicated bioinformatic tool to identify target sequences in genes of a given genome. This software was applied to demonstrate the potential of our improved tools in M. bovis and other mycoplasmas of veterinary and human interest that currently lack genome editing methods.

Rabies remains a significantly underreported fatal zoonosis in India, where the Arctic-like 1a (AL1a) lineage predominates in dog populations. While atypical clinical presentations in dogs can delay diagnosis and increase human exposure risk, genomic and clinical data on neonatal canine rabies remain limited. This study reports an exceptional case of rabies in a 54-day old unvaccinated German shepherd puppy which presented with severe pruritus and self-biting behaviour. The puppy was euthanized due to poor clinical response. Post-mortem testing revealed viral antigen (by Direct Fluorescent Antibody Test) and viral RNA (by real-time RTPCR) in the brain tissue. Whole-genome sequencing recovered a near-complete rabies virus genome (11,947 nucleotides; 99.5% genome coverage), classified within the AL1a_A1.1 sublineage. Phylogenetic analysis revealed close genetic relatedness to contemporary Indian rabies virus strains. Comparative genomic analysis identified 4, 3, 6, and 8 non-synonymous substitutions in the phosphoprotein, matrix, glycoprotein, and polymerase genes, respectively. This case is one of the youngest documented cases of canine rabies with atypical manifestations, caused by the AL1a viral clade. Our findings highlight the risks associated with neonatal canine rabies, the need for heightened clinical suspicion in atypical cases, and the importance of genomic surveillance to monitor evolving rabies virus lineages in endemic regions.

Background: Dirofilaria repens is a zoonotic parasite expanding unnoticed across Europe due to climate change. We hypothesised that in this process, the Carpathian Basin has a facilitating effect. Methods: Using 426 georeferenced European cases, the probability of infection occurrence was determined in relation to climatic factors, surface water availability, regional social deprivation, and stray dog population density. To analyse the potential impacts of ecological and social factors (deprivation and stray dog population density), the MaxEnt algorithm, and spatial Empirical Bayes smoothing and Bivariate Local Indicators of Spatial Association (BiLISA) index calculation were employed, respectively. Results: MaxEnt analysis revealed that the mean warmest month temperature (22.8 - 25.1 oC), winter mean minimum temperature (> -2.1 oC), and summer precipitation (28.6 - 231 mm) have the strongest impact on the probability of the parasite's occurrence in Europe. Social factors have significance in the eastern Balkans and the Carpathian Basin, but not in Western Europe. The Carpathian Basin appears to be a hotspot, similar to Mediterranean coastal areas. Furthermore, the Danube Valley acts as an ecological corridor for subtropical vector-borne parasites. Conclusions: Our findings confirm that summer warmth is the primary ecological driver of the parasite's range expansion, which is facilitated by the Carpathian Basin due to climatic and socioeconomic conditions.

Peste des petits ruminants (PPR) is a highly contagious viral disease of small ruminants caused by the peste des petits ruminants virus (PPRV), which is classified into four distinct genetic lineages (I-IV). A critical concern in the recent epidemiological history of PPRV is the rapid and widespread expansion of lineage IV (LIV) across West Africa over the past decade. This dominance suggests a potential adaptive advantage of circulating LIV strains in the regions current epidemiological context. In this study, we obtain the genome sequence of 26 new PPRV samples, including historical (pre-2000) and many recent African LIV isolates, offering the first opportunity to investigate the evolutionary history of LIV in Africa and identify genetic events potentially associated with its recent spread. Phylogenomic analyses implemented on a dataset of 167 curated PPRV genome sequences reveal that the most ancestral LIV group comprises strains circulating in Sub-Saharan Africa (designated clade LIVssa), providing robust evidence for an African origin of lineage IV. Our results further indicate that PPRV strains linked to the recent West African expansion of LIV belong to a specific LIVssa subgroup, termed NigB. We identified multiple signatures of selection pressure within the LIVssa sublineage, particularly in the NigB cluster. Several amino acid substitutions unique to LIVssa or NigB were detected, some of which may impact protein function and warrant prioritised investigation. Additional genomic data are required to confirm the association between the NigB group and the ongoing spread of LIV in West Africa. The evolutionary adaptations observed in LIVssa - potentially enhancing transmission efficiency, host range or pathogenicity - could undermine current disease control strategies in regions where PPR poses significant threats to food security and local economies. Author SummaryPeste des petits ruminants virus (PPRV) infects sheep and goats across Africa, Middle East, Asia and Europe, causing disease with major impact on global economy and food security. One genetic lineage of PPRV, called lineage IV (LIV), is at the origin of most recent expansion of the distribution of the disease, including replacement of other lineages in areas of African where PPRV is historically present. Here, we generated genome sequences from PPRV LIV isolates from different dates and places to study the evolution of this genetic lineage and explore whether its recent spread can be associated with the appearance of new mutations in the virus genome. Our results provide evidence that the PPRV LIV originated in Sub-Saharan Africa and identify mutations present only virus isolates currently spready in new regions of Africa. Further research should investigate the impact of these mutations on protein functions and capacity of transmission of PPRV.

ObjectivesTo estimate the pooled prevalence of Wolbachia infection in biting midges (Ceratopogonidae) across Southwest Asia and to evaluate ecological and biological factors associated with infection patterns. Study DesignSystematic review and meta-analysis. MethodsA comprehensive search of international and regional databases (PubMed, Scopus, Web of Science, Embase, SID, MagIran) was conducted without date restriction. Eligible studies included those using molecular techniques to detect Wolbachia in Ceratopogonidae collected from Southwest Asia. Pooled prevalence was calculated using a random-effects model. Subgroup and meta-regression analyses were performed to assess variations by country, species, altitude, habitat type, and sex. Heterogeneity and publication bias were evaluated using I{superscript 2}, Cochrans Q, and Eggers tests in accordance with PRISMA guidelines. ResultsTwenty-four studies comprising 14,832 midges from six countries were included. The pooled prevalence of Wolbachia infection was 32.6% (95% CI: 28.4-36.9%; I{superscript 2}=78.3%). Iran showed the highest prevalence (38.2%), and Culicoides imicola was the most frequently infected species (36.8%). Higher prevalence was associated with lower altitudes (<500 m; P=0.012), rural habitats (P=0.034), and female midges (P=0.008). Limited evidence suggested the presence of cytoplasmic incompatibility and reduced bluetongue virus competence in infected midges. ConclusionsWolbachia infection is common among Ceratopogonidae in Southwest Asia and is influenced by ecological and biological factors. These findings highlight the potential of Wolbachia as a biocontrol tool in regional vector management, underscoring the need for further experimental and strain-level studies.