Search Results (1,794)

Avian influenza viruses continue to pose significant zoonotic and pandemic threat globally, with low-pathogenic avian influenza A(H9N2) being of particular concern due to sustained circulation in poultry, adaptability, and repeated human spillover. This study investigated the detection and genetic characterization of influenza viruses at the animal–human interface in Ghana in 2022, using a nationwide cross-sectional One Health approach. Samples were collected from poultry, pigs, the environment, and animal handlers across backyard farms, commercial farms, and live bird markets. Laboratory testing was conducted using real-time RT-PCR, while statistical associations were assessed using chi-square and logistic regression. Whole-genome sequencing and phylogenetic analysis were performed on selected positive samples. Out of 4056 samples, 1516 were poultry samples. A(H9N2) was detected exclusively in poultry, with a prevalence of 5.67%. The Northern belt recorded the highest prevalence. Live bird markets had significantly higher odds of A(H9N2) detection compared with commercial farms (odds ratio: 15.37, p < 0.0001), while backyard farms had lower odds. Environmental samples were negative. Among animal handlers, one case each of A(H3N2) and SARS-CoV-2 was identified. Phylogenetic analysis demonstrated that Ghanaian strains belonged to clade G1 and possessed mammalian-adaptive markers. These findings highlight ongoing circulation in poultry and the need for sustained One Health surveillance. Full article

Bovine viral diarrhea virus (BVDV) and bovine herpesvirus type 1 (BoHV-1) are major pathogens affecting cattle worldwide, leading to significant economic losses in livestock production systems. This study aimed to estimate the seroprevalence and dual seropositivity of both viruses in dual-purpose cattle in Villavicencio, Colombia. A total of 1000 serum samples were collected from cattle across 30 farms and analyzed using ELISA. Seroprevalence for BVDV ranged from 0.0% to 78.7%, while BoHV-1 ranged from 0.0% to 100.0%. Dual seropositivity with both viruses was observed at the farm level, ranging from 0.0% to 52.2%. At the herd level, 26.7% (8/30) of the farms were seronegative for BVDV (95% CI: 14.2–44.5%), whereas only 3.3% (1/30) were seronegative for BoHV-1 (95% CI: 0.6–16.7%). Additionally, seven farms (23.3%) were simultaneously seronegative for both BVDV and BoHV-1. Overall, the findings demonstrate widespread exposure and non-random concurrent seropositivity of both viruses, highlighting the importance of herd management, biosecurity, and animal movement in shaping infection dynamics in dual-purpose cattle systems. Management practices, animal movement, and environmental factors were significantly associated with seropositivity. Full article

Eastern, Venezuelan, and Western equine encephalitis viruses (EEEV, VEEV, and WEEV) are encephalitic alphaviruses transmitted by mosquitoes throughout the Americas. Infection by these viruses can present in humans as a febrile illness; however, it may progress into potentially life-threatening encephalitis. Currently, no publicly licensed vaccines are available, and at-risk individuals are restricted to superseded vaccines. Here, we will review recent advances in our understanding of how these viruses spread among animal populations and cause disease, and how we can manage their diagnosis and treatment. Additionally, we have summarised the recent developments in vaccines against these viruses in both pre-clinical and clinical stages. Overall, global climate change and ecological disruption drive a need for public access to safe and effective vaccines against EEEV, VEEV, and WEEV, which novel platforms, such as mRNA and viral vectors, may be able to achieve. Full article

Hemorrhagic pneumonia is a severe and often fatal disease in captive forest musk deer (Moschus berezovskii), but the pathogen remains incompletely understood. Based on incomplete statistics, the estimated incidence in captive populations ranges from 20% to 80%, with the disease occurring mainly in autumn, winter, and early spring. The disease has an acute onset and rapid progression. Due to the species’ strong stress response, affected animals rarely show behavioral changes, making early detection difficult. In this study, we investigated a mortality case presenting with oral bleeding and hematemesis on a forest musk deer farm. Postmortem examination revealed diffuse hemorrhagic pneumonia, and lung tissue samples were collected for histopathology, bacterial isolation, full-length 16S rRNA gene sequencing, and DNA/RNA virome sequencing. Histological examination showed extensive alveolar hemorrhage, fibrinous exudate, and macrophage infiltration. Bacterial culture and 16S rRNA gene sequencing identified Bergeyella zoohelcum as the predominant bacterium, accounting for 100% of the bacterial community in the lung tissue. Virome analysis revealed predominantly DNA bacteriophages (e.g., Cirlivirales, Cremevirales, Microviridae) and no known pathogenic RNA viruses; only seven low-abundance, unclassified RNA viral contigs of low completeness were detected. These results indicate that B. zoohelcum is the likely causative agent of hemorrhagic pneumonia in this case, with no evidence of viral involvement. This study provides the first direct association of B. zoohelcum with hemorrhagic pneumonia in forest musk deer, highlighting its pathogenic potential and the importance of monitoring this bacterium in captive populations. Full article

Influenza viruses continue to pose a significant threat to both animal and public health due to their rapid evolution and the frequent emergence of antiviral resistance. Host-directed antiviral (HDA) strategies, which target host factors essential for viral replication, may represent an alternative to conventional virus-targeting approaches. However, the identification of reliable and therapeutically actionable host targets remains a major challenge, primarily due to the complexity and context dependency of host–virus interactions. Recent advancements in multi-omics technologies, including functional genomics, transcriptomics, and proteomics, have facilitated the systematic characterization of host factors involved in influenza virus infection. These methodologies have unveiled intricate regulatory networks that govern viral replication and host immune responses. Nonetheless, translating large-scale datasets into biologically meaningful targets necessitates robust integrative frameworks. In this context, artificial intelligence (AI) and machine learning methods offer powerful tools for data integration, target prioritization, and predictive modeling. In this Review, we summarize current insights into host factors that regulate influenza virus infection and discuss how multi-omics and AI-driven approaches are expediting host target discovery. Furthermore, we highlight the potential of these strategies to enhance antiviral development while addressing key challenges related to specificity, safety, and translational application. Collectively, these advancements lay a foundation that may support the rational design of next-generation host-directed antivirals. Full article

Poxviruses are large double-stranded DNA (dsDNA) viruses that cause important human and animal diseases, including smallpox and mpox. Poxviruses have also been identified in diverse bat populations; however, their potential for zoonotic transmission and adaptation to other mammalian hosts remains poorly understood. Poxviruses encode numerous immunomodulatory proteins that contribute to virulence, immune evasion, and host range. In this study, we performed a comparative genomic analysis of two bat-associated poxviruses belonging to the genus Vespertilionpoxvirus: hypsugopox virus (HYPV) and eptesipox virus (EPTV). Our analyses revealed 24 novel putative ORFs in HYPV and three in EPTV, thereby substantially expanding the inferred coding capacity of these viruses. Comparative analyses further revealed gene duplication and fragmentation events affecting several virulence and host range factors, as well as other unusual genomic features, including the presence of two divergent E3L homologs in EPTV. Together, our findings provide new insights into the genome evolution and potential host adaptation of bat-associated poxviruses and establish a foundation for future functional studies of Vespertilionpoxvirus biology, host–virus interactions, and zoonotic potential. Full article

Background/Objectives: Emerging viral zoonoses represent a growing threat to global public health, with most newly emerging infectious diseases originating from animal reservoirs. Recent outbreaks of monkeypox, Ebola virus disease, Marburg virus disease, Rift Valley fever, and avian influenza highlight the capacity of zoonotic viruses to cross species barriers, spread internationally, and generate substantial health, social, and economic consequences. This review examines the ecological, epidemiological, and biological determinants of viral zoonotic emergence and transmission, with particular emphasis on vaccination and outbreak prevention strategies. Methods: A structured narrative review was conducted using a predefined literature search strategy across major scientific databases. Peer-reviewed epidemiological, clinical, and public health publications published between January 2000 and February 2026 were screened and selected according to predefined relevance criteria. Results: The emergence of viral zoonoses is driven by complex interactions among animal reservoirs, environmental and climatic changes, human behavior, and viral adaptation. Although transmission pathways and clinical outcomes differ among pathogens, common determinants of spillover and outbreak amplification were identified. Current evidence supports the importance of integrated surveillance, genomic monitoring, vaccination strategies, and community engagement as key components of preparedness and response. Emerging preventive approaches targeting pathogen transmission, including transmission-blocking strategies and vector-associated microbiota interventions, may provide additional opportunities for disease control. Conclusions: Strengthening preparedness for emerging viral zoonoses requires coordinated One Health approaches integrating human, animal, and environmental health. Future priorities include the development of next-generation vaccines, expansion of digital and genomic surveillance systems, improved equitable access to vaccines, and innovative interventions aimed at reducing zoonotic spillover and interrupting pathogen transmission. Full article

Freshwater amphipods of the genus Gammarus are important trophic components of aquatic ecosystems and are increasingly considered a potential bioresource for aquaculture. However, their role in the maintenance and transmission of infectious agents remains poorly understood. This study evaluated the presence of major crustacean and fish pathogens in Gammarus lacustris populations from Kazakhstan and characterized associated viral communities using metagenomic sequencing. Six pooled samples collected from freshwater ecosystems across Kazakhstan were screened using PCR and RT-PCR assays targeting World Organisation for Animal Health (WOAH)-listed pathogens, including White Spot Syndrome Virus, Taura Syndrome Virus, Infectious Myonecrosis Virus, Aphanomyces astaci, and Aphanomyces invadans. In parallel, high-throughput sequencing (Illumina NovaSeq) was performed to assess virome composition and structure. No WOAH-listed pathogens were detected, suggesting a low detectable occurrence of major notifiable agents under the conditions of the present study. Metagenomic analysis revealed a virome dominated by RNA viruses, particularly picorna-like viruses (Picornaviridae), Dicistroviridae, and Marnaviridae. Phylogenetic and genome organization analyses identified potentially novel or highly divergent viral lineages within Picornavirales. Collectively, these findings suggest a favorable epizootiological profile of G. lacustris populations while highlighting freshwater amphipods as hosts of diverse and partially uncharacterized viral communities relevant to aquatic disease surveillance and aquaculture biosecurity. Full article

Wild boar populations are increasingly recognized as important hosts in the ecology of swine viruses, yet data from Croatia remain limited. This study aimed to establish baseline information on the presence of porcine bocavirus (PBoV) and porcine cytomegalovirus (PCMV) in Croatian wild boar within the framework of the national African swine fever (ASF) surveillance program. Spleen and blood samples from 184 ASF-negative wild boar collected across 11 counties were tested using real-time PCR. PCMV DNA was detected in 16 animals (8.69%), with similar detection frequencies in spleen (7.69%) and blood (9.52%). PBoV DNA was identified in seven animals (3.80%), all from spleen samples. Positive animals were distributed across several counties, but no significant associations were observed between virus detection and age, sex, or geographic origin. Coinfection with both viruses was detected in a single animal (0.05%). These findings provide the first molecular evidence of PBoV and PCMV in Croatian wild boar and indicate low-level viral circulation across multiple regions. Although both viruses are typically subclinical, their detection contributes to understanding pathogen diversity in free-living suids and establishes a foundation for future epidemiological and molecular studies in the region. Full article

Adenoviral vectors are widely used for gene therapy and vaccine development. To circumvent pre-existing immunity against commonly used human adenovirus type 5, vectors based on rare human serotype or animal adenoviruses have attracted increasing interest. Previously, we constructed vectors based on fowl adenovirus 4 (FAdV-4) and replaced the knob of FAdV-4 fiber2 with that of FAdV-1 fiber1 to generate FAdV4-CF1K vectors with enhanced transduction efficiency in human cells. In this study, we aimed to modify the packaging system to efficiently produce FAdV-4 vectors carrying transgenes toxic to viral replication. Chicken LMH cells failed to form colonies at low seeding densities. We collected used medium from LMH cell cultures and used it as a supplement to adapt LMH cells, generating the colony-competent subclone LMH-C3532. A lentiviral vector encoding a codon-optimized tetracycline repressor (tetR) was transduced into LMH-C3532 to establish a tetR-integrated cell line, LMH-tetR24. An adenoviral plasmid, pKFAV4-CF1K-CtG, was constructed in which a tetracycline operator (tetO)-bearing CMV promoter controlled GFP expression. The SwaI-flanked GFP in this plasmid was replaced with the HA gene from an H5N1 influenza virus to generate pKFAV4-CF1K-CtHA. Linearized adenoviral plasmids were transfected into LMH-tetR24 cells, and recombinant FAdV4-CF1K-CtG and FAdV4-CF1K-CtHA viruses were successfully rescued, amplified, and purified. When infected with FAdV4-CF1K-CtG at various multiplicities of infection (MOI), the progeny virus yield from LMH-tetR24 cells was 4–10 times higher than that from LMH-C3532 cells. For FAdV4-CF1K-CtHA, the yield difference between the two cell lines was even more pronounced, reaching 3–4 orders of magnitude. Overexpression of HA in LMH-C3532 cells negatively affected FAdV4-CF1K-CtHA replication, resulting in smaller and fewer plaques. In conclusion, by separately integrating tetR into packaging cells and TetO into the adenoviral plasmid, we established a system that can be routinely used to package FAdV-4 vectors. Notably, this system facilitates the propagation of FAdV-4 vectors carrying toxic transgenes. Full article

Dairy cows are economically significant ruminants in China, and the dairy industry is closely linked to food safety and the agricultural economy. However, various factors such as pathogenic microorganisms often lead to frequent diseases in dairy cows. Furthermore, as potential hosts for diverse viruses, dairy cows can harbor zoonotic pathogens, which pose a threat to public health. The Shaanxi–Gansu–Ningxia region boasts abundant natural resources and extensive pastures. It is a major animal husbandry base in Northwest China, and dairy farming plays a significant role in the local economy. However, research on dairy cow virus diversity in this region remains limited; epidemic prevention and control capabilities are constrained, and the risk of disease outbreaks is elevated. In this study, 790 dairy cow samples were collected from 13 large-scale farms and free-range households in the Shaanxi–Gansu–Ningxia region from 2021 to 2023. Sample types consisted of nasal and anal swabs. Six viral metagenomic libraries were constructed and analyzed using high-throughput sequencing and bioinformatics methods, leading to the identification of 51 viral families. These comprised 16 positive-sense single-stranded RNA virus families, one Retroviridae family, four double-stranded RNA virus families, 21 double-stranded DNA virus families, and nine single-stranded DNA virus families. Among these, RNA viruses were represented by families such as Astroviridae, Coronaviridae, Caliciviridae, Picornaviridae, and Picobirnaviridae; DNA viruses were primarily detected in Circoviridae, Papillomaviridae, Genomoviridae, and Smacoviridae. Alpha diversity analysis revealed no significant differences in viral diversity and abundance among the three regions (p > 0.05); however, significant differences were observed in the read counts and proportions of RNA and DNA viruses across the provinces. Phylogenetic analysis further indicated that viruses carried by dairy cows exhibit considerable genetic diversity and pose potential cross-species transmission risks. This study established a reference database for the dairy cow virome in the Shaanxi–Gansu–Ningxia region, elucidated the phylogenetic relationships of key viruses, and provided a scientific basis for future monitoring and prevention of dairy cow viruses. Full article

Salmonella remains one of the most critical zoonotic pathogens in the poultry sector, linked to animal disease, foodborne illness, and the global crisis of antimicrobial resistance (AMR). Poultry acts as a major reservoir, enabling Salmonella transmission from hatchery to retail products through horizontal, vertical, and environmental routes. Despite the use of biosecurity, vaccination, antibiotics, and chemical decontamination, effective and sustainable control across the poultry value chain remains difficult, particularly in the face of rising multidrug-resistant strains and growing consumer concerns over chemical residues. Bacteriophages (phages), viruses that selectively infect and lyse bacteria, have emerged as a promising biological alternative for Salmonella control. Although many studies have reported the effectiveness of phages against bacterial species, including Salmonella, in the poultry industry, reports on their full potential to combat antimicrobial-resistant Salmonella across the entire poultry value chain remain limited. Therefore, this review synthesizes current evidence on the application of phages throughout the poultry value chain, including on-farm interventions, processing plant decontamination, and food packaging and storage. Findings from the reviewed articles indicate over a 90% reduction in Salmonella spp. in poultry farms and post-harvest meat, along with lower mortality in phage-treated groups compared to untreated groups; however, these outcomes depend on several factors (e.g., phage strains, concentrations, application methods, and environmental conditions). Laboratory, pilot, and field studies consistently demonstrate that phage preparations, especially when formulated as cocktails or combined with complementary interventions, can achieve substantial reductions in Salmonella, including antibiotic-resistant serovars, in live birds, eggs, poultry environments, and meat products. Unlike antibiotics and chemical sanitizers, phages act with high specificity, preserving beneficial microbiota and maintaining the sensory and nutritional quality of poultry products. Their safety has been supported by toxicological and genomic assessments, and several phage-based products have obtained regulatory approval, including Generally Recognized as Safe (GRAS) status for food applications in the United States. By integrating efficacy, safety, regulatory, and practical deployment data, this review highlights bacteriophages as a scientifically validated and One Health–aligned tool capable of reducing Salmonella transmission from farm to fork across the poultry value chain, thereby laying the foundation for their future adoption in the poultry industry. Phage-based interventions offer a sustainable pathway to enhance food safety, limit antimicrobial resistance (AMR) dissemination, and strengthen consumer confidence in poultry products. However, the major limitation is the emergence of phage-resistant bacterial strains, as well as the potential involvement of some phages in the transfer of resistance and virulence genes, which could raise public concern. Nevertheless, the use of phage cocktails and whole-genome sequencing, involving tools such as ResFinder and virulence finder, can facilitate the selection of safe phages for application. Full article

Plateau waters in Northern Sichuan, China, act as critical headwaters of the Yellow River. Microbial communities in water bodies and soil matrices within this region are increasingly pressured by intensive animal rearing; yet few studies have characterized microbial shifts across entire riverine niches. In this study, we employed next-generation sequencing based metagenomics to investigate microbial features, community structure and diversity, metabolic potentials, and antibiotic resistance genes (ARGs) in the Baihe River, a tributary in the source region of the Yellow River. Sampling locations covered the main stem and three tributaries of the Baihe River, spanning from its source, through upstream and downstream segments, to the convergence site with the main stem of the Yellow River. Results revealed that Pseudomonadota and Bacteroidota were the most abundant phyla. The relative abundance of most taxa at multiple taxonomic levels exhibited an increasing trend along the river continuum driven by rising total nitrogen (TN) and total phosphorus (TP) concentrations; however, a notable exception occurred at BH1 (the Baihe source), where the abundance of numerous taxa was markedly higher than in downstream samples. We detected abundant ARGs predominantly associated with antibiotic resistance. Furthermore, prevalent viruses affiliated with the phyla Uroviricota and Nucleocytoviricota, together with pathogenic bacteria, were identified as etiological agents of diverse infectious diseases. This study provides novel perspectives for managing aquatic contamination in plateau river ecosystems by linking environmental variables, microbial succession, and resistome distribution. Full article

In Cambodia, livestock production plays an important role in the national economy and food security, yet tick-borne diseases remain an underrecognized constraint on animal health and productivity. Domestic animals may also serve as reservoirs of zoonotic pathogens in this predominantly rural setting. To address the lack of baseline molecular data on tick-borne pathogens in Cambodia, we conducted a cross-sectional study of ticks collected from November 2022 to April 2023 across 24 provinces. Ticks were collected from various hosts and environments, including cats, cattle, dogs, goats, pangolins, pythons, wild pigs, and bat cave floors, representing urban, rural, farm, wildlife rescue center, and forest fringe habitats. A total of 1526 ticks belonging to nine species were pooled into 352 samples and screened using conventional PCR (cPCR) targeting Anaplasma, Ehrlichia, Babesia, and Coxiella. Additionally, a subset of Rhipicephalus microplus ticks was analyzed using metatranscriptomic next-generation sequencing (NGS). Rhipicephalus microplus ticks collected from cattle tested positive for Anaplasma marginale (1.1% of pools) and Ehrlichia minasensis (0.9% of pools), whereas Rhipicephalus linnaei ticks collected from dogs were positive for Anaplasma platys (0.3% of pools) and Babesia canis (2.0% of pools). A high prevalence of Coxiella-like endosymbionts (15.6% of pools) was found in R. microplus from both cattle and goats. Metatranscriptomic analysis also identified six tick-associated viruses in R. microplus from cattle; with Guangdong tick manly virus being the most dominant (32.5% of samples); followed by Zhangzhou Totiv tick virus 1 (15.0%), Jingmen tick virus (5.0%), and Mogiana tick virus; Rhipicephalus-associated rhabdo-like virus; and Rhipicephalus-associated flavi-like virus; each at 2.5%. These findings provide the first molecular evidence of numerous bacterial, protozoal, and viral pathogens circulating in R. microplus and R. linnaei in Cambodia. The study highlights the need for integrated One Health surveillance to better understand, prevent, and control tick-borne diseases in the region. Full article

Ricin is considered a chemical and biological weapon. It is found in the seeds of a plant, Ricinus communis. There are different isoforms of ricin with different levels of toxicity, depending on the R. communis plant. There is no current prophylaxis and specific treatment for ricin poisoning is recent. Assessing potential countermeasures against this toxin still relies on testing on vertebrate animal models. Galleria mellonella larva, already used for the testing of bacteria, viruses, and fungi, represents an alternative model that is more ethical, inexpensive, and easier to use. In this study, we demonstrated for the first time the sensitivity of G. mellonella larvae to different cultivars of ricin. We observed mortality and a reduction in health index scoring over the days of testing. The health index scoring was based on the survival, the melanization, the mobility, and the capacity of larvae to produce a cocoon or not. Mortality was cultivar- and dose-dependent. Mortality of G. mellonella larvae was reduced when they were treated with a monoclonal antibody and concomitantly injected with ricin. Thus, G. mellonella represents a rapid and simple model of ricin poisoning, and, more particularly, a relevant model to test new therapeutics against ricin. Full article