Transboundary and Emerging Diseases最新文献

Rotavirus (RV) is a significant zoonotic pathogen primarily causing severe diarrheal disease in humans and animals, posing substantial risks to global public health and livestock industries. VP4 is one of the outer capsid proteins of RV and plays a crucial role in RV attachment and internalization. Additionally, it is also involved in replication and immune responses during RV infection; however, related studies are still limited. Here, a comprehensive analysis of the RV VP4 interactome was conducted, and DDX3X, one of six DExD/H helicase family members identified as interacting with VP4, potentially plays a crucial role in RV infection. Silencing DDX3X inhibits RV infection, whereas its overexpression facilitates RV infection. Further research demonstrated that VP4 interacts with DDX3X and the enzymatic activity of DDX3X was found to contribute to promote RV replication. Additionally, a drug screening study based on the VP4 interactome identified RK-33, a potent inhibitor of DDX3X, as the most effective candidate compound for inhibiting RV. In conclusion, VP4 interacts with DDX3X and the enzymatic activity of DDX3X is crucial for RV replication. The DDX3X inhibitor RK-33 exhibits significant inhibitory effects on RV infection. This study highlights the important roles of DDX3X in RV infection, offering potential candidate drugs for RV and expanding our understanding of its mechanisms.

China is the largest pork producer and consumer in the world, and the prevention and control of swine diseases are crucial for ensuring the sustainable and healthy development of the industry. Since 2019, China has initiated pilot programs for a regional prevention and control (RPC) policy targeting major animal diseases, aiming to effectively control African swine fever (ASF) and other significant swine diseases, while promoting high-quality development of the pig industry. This study uses provincial panel data from China spanning 2017–2021, treating the implementation of RPC as a quasinatural experiment, and employs a difference-in-differences (DID) approach to empirically examine the policy’s impact on swine disease spread and its underlying mechanisms. The results indicate that first, RPC significantly reduces swine disease transmission, with provinces implementing the policy showing an average decrease of approximately 69.4% in swine disease levels compared to provinces that did not adopt the policy. Second, the mechanism analysis demonstrates that domestic swine trade partially mediates the policy’s effects; by restricting long-distance interprovincial transport, the policy reduces regional swine trade volumes, thereby effectively curbing disease transmission. Swine farming scale and local slaughtering capacity did not show significant mediating effects, indicating that the policy’s effectiveness primarily depends on controlling the distribution channels rather than directly intervening in production processes. This study provides quantitative evidence on the effectiveness of RPC and offers insights for optimizing and improving future animal disease control policies.

As a local breed adapted to the extreme environment of the Tibetan Plateau, Tibetan pigs have not yet been systematically characterized in terms of their gut viral communities. In this study, we applied viral metagenomics to sequence fecal samples from 191 Tibetan pigs (including both healthy and diarrheal individuals) across four farms in Nyingchi, Tibet, aiming to reveal the diversity, composition, and distribution of gut viral communities in Tibetan pigs living at high altitudes. A total of nearly 120 million high-quality viral sequence reads were obtained, which were annotated into 16 viral families. The viral community was predominantly dominated by Microviridae, but its composition varied across different farms and health statuses. Phylogenetic analysis identified numerous virus sequences associated with pigs, including RNA viruses (such as Astroviridae (n = 7), Caliciviridae (n = 6), Picornaviridae (n = 15), etc.) and DNA viruses (such as Circoviridae (n = 3), Genomoviridae (n = 4), Smacoviridae (n = 41), Parvoviridae (n = 11), etc.). Notably, the study found multiple viral sequences exhibiting genetic differences from known strains, suggesting the potential presence of novel viruses or variants. For instance, a papain-like protease (PLP) insertion sequence, identified to have high sequence identity with Torovirus (ToV), was found in six Enterovirus G (EV-G) strains, indicating a cross-family genetic recombination event. This study systematically outlines the viral metagenomic profile of gut viral communities in Tibetan pigs at high altitudes, revealing their unique viral diversity and complex community structure. The results suggest that the gut viral community of Tibetan pigs consists of host-associated viruses, bacteriophages, and potentially viruses originating from the environment or diet, with its composition influenced by farming conditions and host health status. These findings provide an important data foundation for understanding the interactions between viruses, hosts, and the environment in unique ecological settings and offer new insights into the health management and virology research of Tibetan pigs.

Respiratory syncytial virus (RSV), a major cause of acute respiratory infections (ARIs) globally, poses a significant threat, especially to vulnerable populations. However, the spatial transmission dynamics of RSV strains, including the influence of environmental and socioeconomic factors, remain inadequately understood. This study applied genetic sequences and phylogenetic methods to quantify evolutionary and spatial dispersal dynamics of RSV subgroup A (RSVA) across China from 2011 to 2019. We assessed viral population trends, mapped interprovincial transmission patterns, and evaluated the influence of meteorological and socioeconomic factors on viral spread. Our results revealed cyclical fluctuations in effective population size every 3–5 years, and a predominant southward spread driven by interprovincial transmission networks. We found that higher winter relative humidity (RH), urbanization rate, and human mobility promoted viral spread, while higher winter temperature and elevated urban population density appeared to inhibit it. These findings provide crucial insights into RSVA dispersal in China, underscoring the importance of regional surveillance networks and targeted interventions to curb cross-regional spread, and offer a valuable framework to inform RSV vaccine rollout strategies and guide resource allocation in high-risk areas.

Influenza A virus (IAV) can infect a wide range of hosts, including wild and domestic pigs. Swine play an important role in influenza evolution and epidemiology due to their ability to get infected with both avian and human influenza viruses, potentially leading to reassorted virus variants. Interactions at the wild-domestic swine interface have been documented on multiple occasions, raising concern about pathogen transmission and the emergence of novel influenza strains. This study investigates the occurrence and subtypes of IAV infecting invasive wild pigs in Alberta, Canada. A total of 267 wild pigs were captured between 2021–2024. Exposure to IAV was initially detected by cELISA, with further confirmation of exposure to the H5Nx virus by hemagglutination inhibition (HI) and virus neutralization (VN) assays. Although no IAV genetic material was detected by qPCR, the seropositive samples by cELISA (4.17%; 5/120) coincided with the 2022–2024 highly pathogenic avian influenza virus (HPAI) H5N1 epizootic in Alberta, which involved outbreaks in wild species and domestic birds. These findings, combined with the epidemiological context, suggest interspecies transmission of HPAI H5N1 clade 2.3.4.4b to wild pigs. These results highlight the potential role of wild pigs as a new host in Canada and emphasize the need for continued surveillance of IAV in wild pig populations to assess the risk of spillover events at the wildlife, livestock, and human interfaces.

Tibet orbivirus (TIBOV) is an orbivirus transmitted by mosquitoes and Culicoides, despite specific neutralizing antibodies being detected in pigs, but the molecular genetic characteristics of TIBOV strains in infected pigs are completely uncharted, and their pathogenicity in piglets is poorly elucidated. This study aimed to investigate the genetic characteristics of TIBOV in infected pigs and evaluate the pathogenicity of TIBOV in weaned piglets. Through viral metagenomic sequencing, seven segments (VP1-VP4, VP6, NS1, and NS2) of TIBOV were obtained from swine tissues, and the sequences showed high identity with TIBOVs isolated from Culicoides, mosquitos, and cattle. After infection with TIBOV, the body temperature, appetite, and behavior of the piglets were normal, whereas hemorrhage nodes were observed on the hooves of all piglets and on the abdominal skin of one pig. Viremia was first detected at 2 days postinfection (dpi), peaked at 6 dpi, and remained high until 21 dpi. The virus was distributed in multiple organs, and the highest viral load and strongest viral nucleic acid signals were observed in the spleen. The most severe lesion was observed in the spleen with white pulp atrophy, a decreased number of lymphocytes, and widened septa of the medullary cord, indicating that the spleen was the most important target organ of TIBOV infection. The levels of inflammatory cytokines, including interleukin (IL)-18, tumor necrosis factor-α (TNF-α), interferon (IFN)-α, and IFN-λ3 in peripheral blood lymphocytes decreased significantly from 2 to 6 dpi, and interferon-stimulated gene-15 (ISG-15) and IFN regulatory factor 7 (IRF-7) expression levels declined significantly from 2 to 9 dpi, suggesting that the host immune response was inhibited within 6 dpi. Our findings confirmed that TIBOV elicited long-term viremia with mild clinical symptoms in piglets, the spleen was the target organ of TIBOV proliferation, and the host immune response may be slightly inhibited in the early stage of viral infection.

Foot-and-mouth disease (FMD) is a highly contagious viral illness that continues to threaten livestock health, productivity, and trade, particularly in countries like Türkiye where multiple FMD serotypes cocirculate. This study aimed to analyze the temporal and spatial distributions, serotype dynamics, and seasonal patterns of FMD in Türkiye between 2005 and 2025. The geographical distribution of national FMD surveillance data spanning 2005–2025 was analyzed, together with a time series analysis to evaluate trends and seasonality in the number of FMD-reported outbreaks (number of villages affected by FMD outbreaks). Additionally, event-driven outbreaks were assessed by analyzing the number of reported outbreaks when a serotype introduction occurred and during Kurban Bayramı festivities. The results showed that the number of FMD-reported outbreaks peaked between 2010 and 2016, with serotype O accounting for the majority of reported outbreaks. A decline in outbreaks followed, likely attributable to expanded vaccination coverage, improved diagnostic capacity, and the implementation of targeted control measures. Seasonal patterns indicated a higher concentration of outbreaks during the spring months. Furthermore, it was noted that introductions of serotypes, lineages, or sublineages contributed to an increase in outbreaks in the months surrounding these events, and the same was observed when Kurban Bayramı festivities occurred. Although Türkiye has made progress in reducing the FMD burden, the emergence of new serotypes highlights the ongoing risk of serotype diversification and underscores the need for adaptable, serotype-specific surveillance, and control strategies. Strengthening early detection systems, maintaining high vaccine coverage, and fostering regional cooperation remain essential for sustainable FMD management.

Lumpy skin disease (LSD) is a transboundary viral disease affecting cattle and buffaloes caused by LSD virus (LSDV), which belongs to the Capripoxvirus genus. The disease was first detected in Bangladesh in 2019 and has since become endemic. This study focuses on analyzing the spatiotemporal distribution of LSD cases and examining the relationships between LSD incidence and climatic variables using data collected from 2020 to 2023 in Bangladesh. LSD incidence data from the Department of Livestock Services (DLS) and climate data from the Bangladesh Meteorological Department (BMD) were analyzed via descriptive statistics, box plots, and spatial methods. Hotspots were identified via Getis-Ord Gi^∗ statistics (Gi^∗), whereas Global Moran’s I and local indicators of spatial association (LISA) detected spatial autocorrelation. Associations with climate variables were assessed using Spearman’s correlation and modeled through Poisson, quasi-Poisson, and negative binomial regressions. LSD cases in Bangladesh exhibited substantial temporal and spatial variability between 2020 and 2023, with the highest peaks occurring in 2023, mainly from May to November. Spatial analyses revealed evolving hotspots shifting from southeastern coastal districts (e.g., Chattogram, Cox’s Bazar) to northern and northwestern regions (e.g., Rajshahi, Rangpur) over time. Spearman’s rank correlation revealed significant positive associations between LSD cases and rainfall (r = 0.29), relative humidity (r = 0.37), minimum temperature (r = 0.29), and wind speed (r = 0.22). Regression analyses revealed consistent meteorological influences. In the Poisson model, average sunshine (incidence rate ratio [IRR] = 3.57), minimum temperature (IRR = 1.687), and wind speed (IRR = 2.639) significantly increased LSD cases, whereas average temperature had a strong protective effect (IRR = 0.362). This study reveals strong seasonal and climatic influences on LSD outbreaks in Bangladesh, with peaks occurring during the monsoon season and shifting hotspots from southeast to north. These findings emphasize the importance of climate-based surveillance and targeted control measures.

Classical swine fever (CSF) is a highly contagious disease affecting domestic pigs and wild boars, posing a serious threat to the global swine industry. In Japan, CSF re-emerged on a pig farm in Gifu Prefecture in 2018, just 3 years after the country was declared CSF-free. The CSF virus (CSFV) was soon detected in neighboring wild boars and subsequently spread to adjacent areas, leading to further farm outbreaks. Given that long-distance transmission accelerates both spatial expansion and epidemic persistence, we aimed to identify such events during the current Japanese epidemic. Whole-genome sequences were generated for 100 farm isolates and 585 wild boar isolates collected through national surveillance. Putative ancestral strains were inferred for each isolate by comparing single-nucleotide variants (SNVs), and the great-circle distance to the nearest ancestral strain was considered the transmission distance. Six routes exceeding the 99th percentile of the distance distribution (182.2 km) were classified as long-distance transmission events: three involving farms and three involving wild boars. The sources of all these transmission events were identified as infected wild boars. The route to a farm in Okinawa Prefecture (January 2020) was linked to the illegal feeding of unheated food waste containing meat products. No specific sources were identified in the remaining two farm outbreaks. The three introductions into wild boar populations were most plausibly associated with anthropogenic activities, such as the movement of people or vehicles through infected habitats. To the best of our knowledge, this is the first study to comprehensively quantify long-distance CSFV spread across the entire course of the Japanese epidemic (2018–2024). Our findings will inform targeted control measures to prevent farm infections and the inadvertent spread of contaminated material to remote areas.

In recent years, the prevalence of epizootic diseases caused by Getah virus (GETV) has surged in China, raising significant concerns for animal health and posing a potential threat to public health. This study aims to systematically compare the phenotypic and genotypic characteristics of a high-passage attenuated GETV strain (HuN1-P230) with its virulent parental strain (HuN1), elucidating the molecular changes associated with the attenuation process. The HuN1-P230 strain exhibited enhanced replication kinetics, higher viral titers, and a small-plaque phenotype in cell cultures compared to HuN1. Notably, pregnant mice inoculated with HuN1-P230 displayed a 100% survival rate among neonates, in stark contrast to the complete absence of live births observed with the parental HuN1 strain, indicating a highly attenuated virulence phenotype. Furthermore, challenge experiments demonstrated that HuN1-P230 conferred complete protection against the virulent HuN1 strain. Genomic comparative analysis revealed that HuN1-P230 harbored 26 nucleotide mutations relative to HuN1, including 11 silent mutations and 15 amino acid substitutions. Structural analysis of the GETV spike protein indicated that the observed antigenic differences were closely linked to amino acid substitutions located on the viral surface. These findings suggest that the phenotypic changes observed during GETV attenuation are closely associated with specific genetic modifications, providing critical insights into the molecular mechanisms underlying viral attenuation and highlighting the potential of HuN1-P230 as a vaccine candidate.