Search Results (436)

Avian influenza A viruses (AIVs) pose a significant pandemic threat due to their cross-species transmission potential. However, AIV surveillance at the critical “migratory birds–poultry-exposed population” interface remains limited. Between 2021 and 2024, we implemented a prospective One Health surveillance program around Nansi Lake, monitoring AIVs in migratory birds, poultry, and environmental samples, as well as serological investigations against representative AIVs among migratory birds or poultry-exposed subjects. AIVs were detected in 2.1% (30/1417) of migratory bird samples and 10.2% (100/978) of poultry samples. Among these, we identified ten highly pathogenic avian influenza (HPAI) H5 subtype viruses, one HPAI H7N9 virus, and five low pathogenic avian influenza (LPAI) H9N2 viruses. Phylogenetic analysis revealed evidence of frequent genomic reassortment events involving H5 subtype viruses among migratory birds, poultry, and humans. Serological investigation also suggested that both migratory birds and the poultry-exposed population had a higher risk of getting AIV infection than the general control population, especially against the H9N2 virus. Our study emphasizes the importance of strengthening continuous prospective surveillance of AIVs among migratory birds, poultry, and their exposed individuals to prevent and control potential outbreaks. Full article

Influenza viruses are major threats to global health, with potential to cause widespread disease in both humans and animals. Cattle, once considered resistant, are susceptible hosts for multiple influenza viruses, including influenza A, C and D, while no evidence currently supports infection with influenza B virus. Cattle serve not only as natural reservoirs for influenza D virus but also as emerging spillover hosts for highly pathogenic avian influenza A strains like H5N1. Their role in sustaining viral circulation, facilitating interspecies transmission, and potentially contributing to viral evolution raises significant concerns about future global outbreaks. As host immunity controls viral clearance and spread, understanding how cattle respond to influenza is essential. While most research has focused on antibody-mediated immunity, T cells play indispensable roles in controlling influenza infections by regulating antibody response, clearing infected cells, and providing long-term protection. However, bovine T cell responses to influenza remain poorly characterized. Given that most research has focused on mice and humans, this review outlines current knowledge of bovine T cell responses to influenza viruses in comparison to these well-characterized models. Cross-species comparative studies are essential to identify species-specific immunity, guide cattle vaccine development, and build predictive models to evaluate future pandemic potential. Full article

The highly pathogenic avian influenza H5N1 2.3.4.4b clade virus has caused widespread outbreaks across South America, primarily affecting seabirds, poultry, and marine mammals. The virus likely reached the continent through migratory birds from North America, initially spreading along the Pacific coast before advancing into Atlantic-bordering countries such as Argentina, Uruguay, and Brazil. This study investigated the dynamics of H5N1 strains in Uruguay during outbreaks from February and October 2023. We analyzed an updated South American database, including a newly sequenced viral genome from a royal tern (Thalasseus maximus) collected at the end of the outbreaks. Phylogeographic reconstruction revealed two distinct South American phylogroups comprising Uruguayan strains: one mainly driven by wild birds and poultry, with the royal tern strain clustering with Brazilian isolates, and another primarily associated with marine mammals, displaying adaptive residues in the PB2 protein. In Uruguay, these phylogroups delineate two main transmission routes: (i) an avian-derived pathway originating in Argentina and (ii) a pinniped-derived route from Chile. Brazil, initially colonized via the Argentine route, later emerged as a secondary source for Uruguay. This host-pathway interplay underscores the virus’s cross-species potential and highlights the need for coordinated regional surveillance within a One Health framework to mitigate zoonotic risks. Full article

Highly pathogenic avian influenza (HPAI) remains a persistent threat to global poultry production and public health. Current vaccine platforms show limited cross-clade efficacy and often fail to induce mucosal immunity. Recent advances in microbiome research reveal critical roles for gut commensals in modulating vaccine-induced immunity, including enhancement of mucosal IgA production, CD8⁺ T-cell activation, and modulation of systemic immune responses. Engineered commensal bacteria such as Lactococcus lactis, Bacteroides ovatus, Bacillus subtilis, and Staphylococcus epidermidis have emerged as promising live vectors for antigen delivery. Postbiotic and synbiotic strategies further enhance protective efficacy through targeted modulation of the gut microbiota. Additionally, artificial intelligence (AI)-driven tools enable predictive modeling of host–microbiome interactions, antigen design optimization, and early detection of viral antigenic drift. These integrative technologies offer a new framework for mucosal, broadly protective, and field-deployable vaccines for HPAI control. However, species-specific microbiome variation, ecological safety concerns, and scalable manufacturing remain critical challenges. This review synthesizes emerging evidence on microbiome–immune crosstalk, commensal vector platforms, and AI-enhanced vaccine development, emphasizing the urgent need for One Health integration to mitigate zoonotic adaptation and pandemic emergence. Full article

The 2025 avian influenza A(H5N1) outbreak has highlighted the urgent need for rapidly generated health communication materials during public health emergencies. Artificial intelligence (AI) systems offer transformative potential to accelerate content development pipelines while maintaining scientific accuracy and impact. We evaluated an AI-generated health communication material on bird flu precautions among 100 U.S. adults. The material was developed using ChatGPT for text generation based on CDC guidelines and Leonardo.AI for illustrations. Participants rated perceived message effectiveness, quality, realism, relevance, attractiveness, and visual informativeness. The AI-generated health communication material received favorable ratings across all dimensions: perceived message effectiveness (3.83/5, 77%), perceived message quality (3.84/5, 77%), realism (3.72/5, 74%), relevance (3.68/5, 74%), attractiveness (3.62/5, 74%), and visual informativeness (3.35/5 67%). Linear regression analysis revealed that all features significantly predicted perceived message effectiveness in unadjusted and adjusted models (p < 0.0001), e.g., multivariate analysis of outcome on perceived visual informativeness showed β = 0.51, 95% CI: 0.37–0.66, p < 0.0001. Also, mediation analysis revealed that visual informativeness accounted for 23.8% of the relationship between material attractiveness and perceived effectiveness. AI tools can enable real-time adaptation of prevention guidance during epidemiological emergencies while maintaining effective risk communication. Full article

Sin Nombre virus (SNV) is the main causative agent of hantavirus cardiopulmonary syndrome (HCPS) in North America. SNV is transmitted via environmental biological aerosols (bioaerosols) produced by infected deer mice (Peromyscus maniculatus). It is similar to other viruses that have environmental transmission routes rather than a person-to-person transmission route, such as avian influenza (e.g., H5N1) and Lassa fever. Despite the lack of person-to-person transmission, these viruses cause a significant public health and economic burden. However, due to the lack of targeted pharmaceutical preventatives and therapeutics, the recommended approach to prevent SNV infections is to avoid locations that have a combination of low foot traffic, receive minimal natural sunlight, and where P. maniculatus may be found nesting. Consequently, gaining insight into the SNV bioaerosol decay profile is fundamental to the prevention of SNV infections. The Biological Aerosol Reaction Chamber (Bio-ARC) is a flow-through system designed to rapidly expose bioaerosols to environmental conditions (ozone, simulated solar radiation (SSR), humidity, and other gas phase species at stable temperatures) and determine the sensitivity of those particles to simulated ambient conditions. Using this system, we examined the bioaerosol stability of SNV. The virus was found to be susceptible to both simulated solar radiation and ozone under the tested conditions. Comparisons of decay between the virus aerosolized in residual media and in a mouse bedding matrix showed similar results. This study indicates that SNV aerosol particles are susceptible to inactivation by solar radiation and ozone, both of which could be implemented as effective control measures to prevent disease in locations where SNV is endemic. Full article

Avian influenza viruses (AIVs) pose significant risks to occupational populations engaged in poultry farming, livestock handling, and live poultry market operations due to frequent exposure to infected animals and contaminated environments. This review synthesizes evidence on AIV exposure patterns and risk factors through a comprehensive analysis of viral characteristics, host dynamics, environmental influences, and human behaviors. The main routes of transmission include direct animal contact, respiratory contact during slaughter/milking, and environmental contamination (aerosols, raw milk, shared equipment). Risks increase as the virus adapts between species, survives longer in cold/wet conditions, and spreads through wild bird migration (long-distance transmission) and live bird trade (local transmission). Recommended control measures include integrated animal–human–environment surveillance, stringent biosecurity measures, vaccination, and education. These findings underscore the urgent need for global ‘One Health’ collaboration to assess risk and implement preventive measures against potentially pandemic strains of influenza A viruses, especially in light of undetected mild/asymptomatic cases and incomplete knowledge of viral evolution. Full article

Background: Fowl typhoid (FT), a septicemic infection caused by Salmonella Gallinarum (SG), and H9N2 avian influenza are two economically important diseases that significantly affect the global poultry industry. Methods: We exploited the live attenuated Salmonella Gallinarum (SG) mutant JOL3062 (SG: ∆lon ∆pagL ∆asd) as a delivery system for H9N2 antigens to induce an immunoprotective response against both H9N2 and FT. To enhance immune protection against H9N2, a prokaryotic and eukaryotic dual expression plasmid, pJHL270, was employed. The hemagglutinin (HA) consensus sequence from South Korean avian influenza A virus (AIV) was cloned under the Ptrc promoter for prokaryotic expression, and the B cell epitope of neuraminidase (NA) linked with matrix protein 2 (M2e) was placed for eukaryotic expression. In vitro and in vivo expressions of the H9N2 antigens were validated by qRT-PCR and Western blot, respectively. Results: Oral immunization with JOL3121 induced a significant increase in SG and H9N2-specific serum IgY and cloacal swab IgA antibodies, confirming humoral and mucosal immune responses. Furthermore, FACS analysis showed increased CD4+ and CD8+ T cell populations. On day 28 post-immunization, there was a substantial rise in the hemagglutination inhibition titer in the immunized birds, demonstrating neutralization capabilities of immunization. Both IFN-γ and IL-4 demonstrated a significant increase, indicating a balance of Th1 and Th2 responses. Intranasal challenge with the H9N2 Y280 strain resulted in minimal to no clinical signs with significantly lower lung viral titer in the JOL3121 group. Upon SG wildtype challenge, the immunized birds in the JOL3121 group yielded 20% mortality, while 80% mortality was recorded in the PBS control group. Additionally, bacterial load in the spleen and liver was significantly lower in the immunized birds. Conclusions: The current vaccine model, designed with a host-specific pathogen, SG, delivers a robust immune boost that could enhance dual protection against FT and H9N2 infection, both being significant diseases in poultry, as well as ensure public health. Full article

Enteric diseases represent one of the main causes of morbidity and mortality in poultry production, especially in turkeys (Meleagris gallopavo), significantly affecting the profitability of the sector. Turkey enteric complex (PEC) is a multifactorial syndrome characterized by diarrhea, stunting, poor feed conversion, and increased mortality in young turkeys. Its aetiologia includes multiple avian enteric viruses, including astrovirus, rotavirus, reovirus, parvovirus, adenovirus, and coronavirus, which can act singly or in co-infection, increasing clinical severity. This study performs a systematic review of the literature on these viruses and a meta-analysis of their prevalence in different regions of the world. Phylogenetic analyses were used to assess the genetic diversity of the main viruses and their geographical distribution. The results show a wide regional and genetic variability, which underlines the need for continuous epidemiological surveillance. Health and production implications are discussed, proposing control strategies based on biosecurity, targeted vaccination, and optimized nutrition. These findings highlight the importance of integrated management to mitigate the impact of CSF in poultry. Full article

Pasteurella multocida (Pm) is a zoonotic pathogen that poses a significant threat to animal health and causes substantial economic losses, further aggravated by rising tetracycline resistance. To restore the efficacy of tetracyclines to Pm, we evaluated the synergistic antibacterial activity of doxycycline combined with metformin, an FDA-approved antidiabetic agent. Among several non-antibiotic adjuvant candidates, metformin exhibited the most potent in vitro synergy with doxycycline, especially against capsular serogroup A strain (PmA). The combination demonstrated minimal cytotoxicity and hemolysis in both mammalian and avian cells and effectively inhibited resistance development under doxycycline pressure. At 50 mg/kg each, the combination of metformin and doxycycline significantly reduced mortality in mice and ducks acutely infected with PmA (from 100% to 60%), decreased pulmonary bacterial burdens, and alleviated tissue inflammation and damage. Mechanistic validation confirmed that metformin enhances membrane permeability in Pm without compromising membrane integrity, dissipates membrane potential, increases intracellular doxycycline accumulation, and downregulates the transcription of the tetracycline efflux gene tet(B). Morphological analyses further revealed pronounced membrane deformation and possible leakage of intracellular contents. These findings highlight metformin as a potent, low-toxicity tetracycline adjuvant with cross-species efficacy, offering a promising therapeutic approach for managing tetracycline-resistant Pm infections. Full article

The non-traditional companion animal (NTCA) sector, particularly involving avian species, has significantly expanded in Italy, raising concerns over the spread of infectious diseases. These animals can harbor various pathogens and act as reservoirs, posing risks to native wildlife through legal or illegal trade, escapes, or intentional releases. However, the epidemiology of avian pathogens in NTCAs remains poorly understood and is typically investigated only in symptomatic individuals. In the present study, cloacal and choanal cleft swabs were collected from 319 ornamental and raptor birds across 19 families, pooled and tested for beak and feather disease virus (BFDV), avian polyomavirus (APV-1), psittacid herpesvirus 1 (PsHV-1), and avian metapneumovirus (aMPV). BFDV and APV-1 were detected in 13.79% and 2.19% of birds, respectively, with five co-infections. No cases of PsHV-1 or aMPV were found. Both viruses showed a higher prevalence than in previous Italian and most of international studies, with several non-psittacine species, including birds of prey, testing positive—some for the first time. Mixed-species settings and participation in public exhibitions were proven as significant infection risk factors. The study highlights the growing relevance of BFDV and APV-1 in non-commercial birds and recommends improved biosecurity and preventive screening to reduce disease spread and safeguard animal health. Full article

Avian influenza virus (AIV) remains a persistent threat to both the poultry industry and human health. Among the AIV subtypes posing public health threats, H7N9 AIV is responsible for five epidemic waves of human infection in China. Here, a detection system based on a mouse model was established, which can simultaneously and quantitatively analyze the dynamic changes in the viral genomic RNA (vRNA), complementary RNA (cRNA), and messenger RNA (mRNA) of H7N9 AIV by using reverse transcription primers with tag sequences to reverse transcribe the three species of RNAs into corresponding cDNA templates, which are then absolutely quantified using the TaqMan quantitative PCR method. This system specifically targets the PB2 and NA genes and, for the first time, enables a spatiotemporal analysis of all three viral RNA species within an animal model. Our results revealed that H7N9 AIV exhibits characteristic replication kinetics, with all three species of viral RNAs showing a rapid increase followed by a certain degree of decline. This system offers a powerful tool for us to further advance our understanding of the replication dynamics of AIV in mice. Full article

Avian pathogenic Escherichia coli (APEC) poses a global threat to poultry health and public safety due to its high lethality, limited treatment options, and potential for zoonotic transmission via the food chain. However, long-term genomic surveillance remains limited, especially in countries like China where poultry farming is highly intensive. This study aimed to characterize the population structure, virulence traits, and antimicrobial resistance of 81 APEC isolates from diseased chickens collected over 16 years from Shandong and neighboring provinces in eastern China. The isolates were grouped into seven Clermont phylogroups, with A and B1 being dominant. MLST revealed 27 STs, and serotyping identified 29 O and 16 H antigens, showing high genetic diversity. The minor phylogroups (B2, C, D, E, G) encoded more virulence genes and had higher virulence-plasmid ColV carriage, with enrichment for iron-uptake, protectins, and extraintestinal toxins. In contrast, the dominant phylogroups A and B1 primarily carried adhesin and enterotoxin genes. Antimicrobial resistance was widespread: 76.5% of isolates were multidrug-resistant. The minor phylogroups exhibited higher tetracycline resistance (mediated by tet(A)), whereas the major phylogroups showed increased resistance to third- and fourth-generation cephalosporins (due to bla_CTX-M-type ESBL genes). These findings offer crucial data for APEC prevention and control, safeguarding the poultry industry and public health. Full article

Anseriformes (waterfowl) and Charadriiformes (shorebirds) are well-recognized natural reservoirs of low pathogenic (LP) influenza A viruses (IAVs). Historically, LP IAVs circulate among healthy individuals during seasonal, and often transcontinental, migrations. However, following the introduction of clade 2.3.4.4b highly pathogenic (HP) A/Goose/Guangdong/1/1996 lineage H5 IAV to North America in 2021, countless wild birds succumbed to fatal infections across the Western Hemisphere. Due to their small size and cryptic plumage patterns, opportunities for carcass recovery and postmortem evaluation in sanderlings (Calidris alba) and other shorebirds are rare. A multispecies mortality event in coastal Virginia, USA, in March–April 2024 included sanderlings among other wild bird species. Nine sanderlings underwent postmortem evaluation and clade 2.3.4.4b H5 IAV RNA was detected in pooled oropharyngeal-cloacal swabs from 11/11 individuals by real-time reverse transcription polymerase chain reaction. Histopathology was similar to that in waterfowl and included necrosis in the pancreas and brain and less commonly in the gonad, adrenal gland, spleen, liver, and intestine. Immunohistochemistry revealed IAV antigen labeling in necrotic neurons of the brain (neurotropism) and epithelial cells of the pancreas, gonad, and adrenal gland (epitheliotropism). Describing HP IAV-attributed pathology in shorebirds is key to understanding ecoepidemiology and population health threats in order to further document and compare pathogenesis among avian species. Full article

Background/Objectives: Outbreaks of highly pathogenic avian influenza virus (AIV) result in significant financial losses and the death or depopulation of millions of domestic birds. Early and rapid detection and surveillance are needed to slow the spread of AIV and prevent its spillover to humans. The volatile metabolome (i.e., the pattern of volatile metabolites emitted by a living subject) represents one such source of health information that can be monitored for disease diagnosis. Indeed, dogs have been successfully trained to recognize patterns of “body odors” associated with many diseases. Because little is known regarding the mechanisms involved in the alteration of the volatile metabolome in response to health perturbation, questions still arise regarding the specificity, or lack thereof, of these alterations. Methods: To address this concern, we experimentally infected twenty mallard ducks with one of two different strains of low-pathogenic AIV (ten ducks per strain) and collected cloacal swabs at various time points before and after infection. Results: Headspace analyses revealed that four volatiles were significantly altered following infection, with distinct profiles associated with each viral strain. The volatiles that differed between strains among post-infection sampling periods included ethylbenzyl ether (p = 0.00006), 2-phenoxyethanol (p = 0.00017), 2-hydroxybenzaldehyde (p = 0.00022), and 6-methyl-5-hepten-2-one (p = 0.00034). Conclusions: These findings underscore that AIV-induced changes to the volatile metabolome are strain-specific, emphasizing the need for disease-specific profiling in diagnostic development. Full article