Search Results (256)

This study examines how Canadian news media portrayed government-mandated depopulation during Highly Pathogenic Avian Influenza (HPAI) outbreaks and identified patterns in reporting tone and language. English-language Canadian news and magazine articles published between December 2021 and September 2025 were retrieved from ProQuest. Sentiment analysis was conducted separately for article titles and full text using SentiStrength and sentimentr, with a study-specific neutral word list applied. Term frequency–inverse document frequency (TF–IDF) analysis was used to identify distinctive terms in titles and body text, while temporal sentiment patterns were examined in relation to major HPAI outbreak developments and Canadian case counts. A total of 217 articles were included. Overall article body sentiment was near neutral (mean = −0.02) but showed negative shifts during periods of heightened outbreak activity and high-profile events. Title-level sentiment scores were more frequently classified as negative (45.6%) than positive (11.5%). Distinctive terms in reporting included outbreak-related, legal, and institutional terminology. The results suggest that media portrayals of HPAI depopulation varied over time alongside major outbreak developments and policy-related events. Monitoring news reporting may provide insight into communication surrounding animal disease control policies during outbreaks and may help inform communication planning by policymakers, industry organizations, and extension professionals. Full article

In June 2023, Poland experienced an unprecedented outbreak of highly pathogenic avian influenza (HPAI) H5N1 virus infections in cats, raising concerns about the role of cats in HPAI H5N1 virus ecology and potential public health implications. We describe the clinical course and molecular findings in a cat designated as cat No. 14 during this outbreak, with emphasis on the viral load detected in various organs and tissues. The cat was initially examined for recurrent dermatological problems, although the owner also reported reduced activity. Over the following five days, the disease rapidly progressed, with systemic and neurological signs unresponsive to treatment. Blood analyses revealed no major haematological abnormalities, whereas serial serum biochemistry showed progressive abnormalities. Due to the poor prognosis, the cat was humanely euthanized five days after the initial veterinary examination. Tissue samples from major internal organs and lymph nodes, together with tracheal and rectal swabs and bile, were collected for real-time RT-PCR. Viral RNA was detected in all analysed samples except the intestines, mesenteric lymph nodes, rectal swab, and bile, with the highest viral loads observed in the cerebellum and brain. This case provides molecular evidence of widespread HPAI H5N1 viral RNA distribution across tissues, complemented by detailed haematological and biochemical findings, further characterizing the systemic nature of infection. Full article

Highly pathogenic avian influenza (HPAI) represents an enormous pandemic risk amid the ongoing H5N1 panzootic. HPAI, defined by its high lethality in domestic poultry, includes the influenza A virus (IAV) H5N1 and H7N9 subtypes and has a 40–50% case fatality rate in humans. To facilitate the development of efficacious HPAI vaccination regimens and isolation of HPAI-neutralizing monoclonal antibodies (nmAbs) for prophylactic and therapeutic use, we performed a proof-of-concept pilot study wherein we developed an array of mRNA and adenovirus-vectored vaccines encoding HPAI hemagglutinins (HAs) and then assessed their immunogenicity in IAV-naïve Indian rhesus macaques (RMs). All RMs developed binding IgG recognizing both HPAI HAs. HPAI-nAbs were detected in RMs vaccinated with full-length HAs, but not in RMs vaccinated with HA stems alone. Potent HPAI neutralization activity was observed in two animals with serum ID₅₀ titers of ~1:100,000 against H5N1 and ~1:50,000 against H7N9. Most RMs developed cross-reactive IgG recognizing the HAs of additional IAV subtypes, and HA-specific B cells were readily identifiable in vaccinee PBMCs by flow cytometric analysis. The results of our pilot study suggest that elicitation of potent HPAI-nAb responses is enhanced by vaccination with the HA head domain and that vaccination with the HA stem alone tends to elicit binding non-nAbs. Furthermore, use of our fluorophore-conjugated HA probes to identify HA-specific B cells could enable HPAI-nmAb isolation. Collectively, our findings could facilitate the development of novel vaccines and nmAb therapeutics leveraging the superior neutralization potency of HA head-specific Abs to prevent and treat HPAI infections in humans. Full article

This study characterized the long-term changes in reported farm-level fowl typhoid occurrence in the Republic of Korea from 2000 to 2024. Farm-level notification records (n = 1495) were obtained from the national livestock disease database. Annual counts were analyzed on a log(count + 1) scale using segmented linear regression. The number of breakpoints was selected by Bayesian information criterion (BIC) comparison of candidate segmented models, and BIC favored a two-breakpoint model. Breakpoints were estimated at 2009.0 (95% CI, 2004.7–2013.3) and 2016.5 (95% CI, 2014.1–2019.0). Phase 1 (2000–2009) declined significantly (annual percent change [APC], −16.3%; 95% CI, −25.9 to −5.5), Phase 2 (2009–2016) showed no significant change (APC, 3.7%; 95% CI, −10.3 to 20.0), and Phase 3 (2016–2024) showed an accelerated decline (APC, −28.0%; 95% CI, −34.9 to −19.8). Province-specific post-2016 slopes were not associated with cumulative provincial HPAI events during 2014–2024 (Spearman’s ρ = −0.143, p = 0.736). The post-2016 acceleration temporally overlapped with the 2016–2017 H5N6 HPAI epidemic, but the study did not measure the contemporaneous interventions or denominators needed for causal attribution. Full article

Neuraminidase (NA) is a major surface glycoprotein of influenza viruses that mediates the release of progeny virions from infected cells. Although both hemagglutinin (HA) and NA are targets of protective immune responses, current seasonal influenza vaccines are primarily standardized based on HA content, resulting in variable and often suboptimal induction of NA-specific immunity. Therefore, NA is subject to different immune pressures and exhibits distinct patterns of antigenic evolution. Increasing evidence suggests that neuraminidase-inhibiting (NAI) antibodies contribute to protection against influenza by limiting viral replication and reducing disease severity, particularly when HA antibodies are poorly matched to circulating strains. The recent emergence of highly pathogenic avian influenza (HPAI) H5N1 viruses with widespread transmission in dairy cattle and increasing zoonotic infections has renewed interest in understanding the extent of pre-existing human immunity to NA and its potential role in mitigating disease caused by emerging influenza viruses. However, the breadth of cross-reactive NA immunity against zoonotic influenza viruses remains incompletely understood. In this review, we summarize current knowledge of population immunity to influenza NA, with a focus on the roles of immune imprinting, natural infection, and seasonal vaccination in shaping NA-specific antibody responses. We further discuss the cross-reactivity of these antibodies against zoonotic influenza viruses and highlight the implications of NA immunity for pandemic preparedness. Full article

Background: Highly pathogenic avian influenza (HPAI) poses a critical global threat to both the poultry industry and public health. Although Morocco currently maintains HPAI-free status, the country faces substantial risk due to its location along major migratory flyways and its extensive commercial trade networks within the poultry sector. Available data indicate that the links between live bird markets, production farms, and related facilities in the poultry sector constitute a pivotal determinant of disease epidemiology. This study aimed to analyze these movements and determine how they can influence the spread of the disease and to guide policymakers in developing effective risk-based surveillance and control strategies tailored to the local context.: A questionnaire-based cross-sectional survey was conducted across the Casablanca-Settat region, including nine provinces and 138 municipalities, to investigate the movement patterns within the poultry sector in this region. Social network analysis (SNA) was employed to construct a movement network, and findings were spatially visualized using Geographic Information Systems (GIS) and analyzed through network analysis in R.: A total of 945 transport routes were recorded in 126 municipalities. Centrality measures identified three predominant network nodes exhibiting high degree and betweenness centrality values. Our findings indicate that although the network has a low density, the transmission of IAHP remains critical due to frequent bidirectional links and a heterogeneous network structure. The high concentration of movements by a few “hub” municipalities leads to an early emergence and rapid dissemination.: The identification of highly influential nodes allows veterinary authorities to prioritize and target surveillance activities toward municipalities with the greatest likelihood of disease introduction or persistence. The network’s structural connectivity suggests a theoretical potential for rapid HPAI spread, underscoring the importance of the frequent bidirectional links identified between municipalities. This protects both Morocco’s poultry industry and public health. Full article

High-pathogenicity avian influenza (HPAI) remains a recurrent threat to poultry production in the Republic of Korea, but production-type-specific clustering has rarely been assessed against the underlying farm population. This retrospective unmatched case–control point-pattern study examined spatial and space–time clustering across six epidemic seasons from 2020 to 2026. We analyzed 486 reported poultry-farm outbreak records together with a national registry of 66,499 poultry farms. The principal analyses compared 204 layer and 204 duck outbreak events with farms of the same production type using the Cuzick–Edwards k-nearest-neighbor statistic, an observed-to-expected clustering-intensity ratio, kernel relative-risk mapping, and spatial and space–time scan statistics. At k = 5, the observed-to-expected intensity ratio was 2.51 for layer events and 1.63 for duck events; this between-type contrast was descriptive because no direct inferential test was performed. Layer-event clustering remained elevated across all seasons, although the extreme 2023–2024 estimate was based on only 15 events. Duck-event clustering was more intermittent and increased in 2025–2026. Premises-level scan statistics identified a broad layer cluster with a relative risk of 3.12 and a smaller duck cluster with a higher local relative risk but far fewer farms. A layer space–time cluster occurred in 2024–2025. These findings support production-type-specific, density-aware surveillance. They do not establish farm-to-farm transmission or implicate egg-handling infrastructure, and they should be interpreted in light of the static registry, repeated-event design, and unmeasured flock size, movements, biosecurity, environmental exposure, and viral lineage. Full article

Highly pathogenic avian influenza (HPAI) virus H5N1of clade 2.3.4.4b has emerged as the predominant lineage circulating in poultry flocks worldwide, raising concerns regarding the protective efficacy of currently available commercial vaccines, particularly in domestic ducks, which play an important role in virus maintenance and transmission. Thus, this study evaluated the immunogenicity along with the protective efficacy of four inactivated H5 vaccines against a recently isolated local HPAI-H5N1 (Newvalley-3-H5N1-2024, clade 2.3.4.4b) strain in Pekin ducks in Egypt. A total of 150 seronegative ducks were divided into vaccinated and control groups (10 groups) and vaccinated at 10 days of age. At 31 days of age, the vaccinated and positive control groups were challenged using 10^6.5 EID₅₀/0.5 mL/duck with the local isolate (Newvalley-3-H5N1-2024) via the oculo-nasal route. The vaccine efficacy was assessed through clinical signs, survival rate, hemagglutination inhibition (HI) antibody titer, tracheal and cloacal viral shedding quantified by real-time RT-PCR, and histopathological examination of trachea, lung, pancreas, and brain tissues. Generally, all ducks vaccinated with the ValleyVac Avian Flu H5 plus and MEFLUVAC^TM H5 PLUS 8 showed a significantly higher survival rate (100%) at 10 days post-vaccination (DPV) than those in the positive control (66.7% mortality rate). In contrast, ducks exhibited mortality rates ranging from 6.7% in the SERVAC Flu H5N1 group to 13.4% in the Sinder Fluvac group. The ValleyVac Avian Flu H5 plus and MEFLUVAC™ H5 PLUS 8 vaccines induced the highest HI antibody titers at 7, 14, 21, and 28 DPV in both homologous and heterologous AIV antigens, resulting in a significant reduction in viral load among all vaccinated duck groups (p-value < 0.05) comparable to the positive control group. Conversely, the SERVAC Flu H5N1 and Sinder Fluvac vaccines provided partial protection, suboptimal immunogenicity at different time points, and elevated viral shedding. Histopathological findings in ValleyVac Avian Flu H5 plus and MEFLUVAC™ H5 PLUS 8 vaccines exhibited mild tissue alterations following AIV challenge. Marked pathological lesions were observed in the SERVAC Flu H5N1 and Sinder Fluvac vaccinated groups. Among tested vaccines, both ValleyVac Avian Flu H5 plus and MEFLUVAC^TM H5 PLUS 8 showed the highest level of protective efficacy against the circulating AIV strain compared with other commercial vaccines. This study highlights the need for continuous molecular surveillance, antigenic matching, and regular updating of vaccine seed strains to ensure efficient HPAI control in Egypt. Full article

Background: The simultaneous circulation of highly pathogenic avian influenza (HPAI) H5N8 (clade 2.3.4.4b) and virulent Newcastle disease virus (NDV) genotype VII creates a cumulative risk for the poultry industry, rendering monovalent vaccination insufficient. This study aimed to develop and evaluate a combined inactivated vaccine against AIV H5N8 and NDV genotype VII based on local endemic strains. Methods: The vaccine was formulated as a water-in-oil emulsion (30:70) using Montanide™ ISA 78 VG. Evaluation included physicochemical characterization, safety assessment in chickens, immunogenicity evaluation via the hemagglutination inhibition (HI) test, and protective efficacy following challenge with virulent isolates. Results: The formulation demonstrated high stability and complete safety without adverse reactions. By 28 days post-immunization, the vaccine induced a robust, balanced humoral response with antibody titers reaching 9.10 ± 0.23 log₂ against NDV and 9.00 ± 0.26 log₂ against AIV, indicating no antigenic interference. Upon challenge, the vaccinated group exhibited 100% clinical protection and survival, compared to 100% mortality in controls. Furthermore, vaccination significantly reduced viral shedding, limiting horizontal spread. Conclusions: The developed combined inactivated vaccine demonstrates high safety, stability, and protective efficacy. It represents a promising candidate for comprehensive specific prophylaxis in endemic regions, effectively limiting horizontal pathogen transmission and mitigating economic losses in poultry production. Full article

Highly pathogenic avian influenza (HPAI) is a transboundary disease of birds with zoonotic potential. Since 2021, H5 HPAI virus variants have spread globally, with migratory waterfowl playing a key role in transcontinental dissemination. Kazakhstan lies at the intersection of major flyways, creating a persistent risk of virus introduction into domestic poultry. While HPAI risk in wild birds has been explored in Kazakhstan, the spatial risk for poultry has remained underassessed. Here, we present a risk map for HPAI in poultry across 174 administrative districts of Kazakhstan, using a multi-criteria decision analysis (TOPSIS) that integrates five quantitative risk indicators that relate to wild bird habitat, virus survival in the environment and poultry farm census. The obtained district-level risk index agreed well with historical outbreak data (2005–2025), with an area under the receiver operating characteristic (ROC) curve of 0.899 (95% CI: 0.846–0.952). Most districts (56%) were at negligible risk, whereas medium- and high-risk clusters occurred in the north, central, and southern regions, and near the Caspian Sea. These findings provide an operational, spatially explicit tool for targeting surveillance and biosecurity measures to high-risk areas, ultimately helping to mitigate the impact of one of the most devastating transboundary poultry diseases in Central Asia. Full article

Avian influenza is a highly contagious viral disease affecting domestic and wild birds, caused by influenza A viruses of the family Orthomyxoviridae. Continuous genetic surveillance is essential for monitoring viral evolution and identifying molecular determinants associated with pathogenicity and host adaptation. In this study, the PB1 and PB2 polymerase genes of highly pathogenic avian influenza (HPAI) H5N1 viruses detected in Romania between 2017 and 2024 were genetically characterized. A total of 18 organ samples collected from domestic and wild birds in several Romanian counties were analyzed by real-time RT-PCR, followed by conventional RT-PCR, Sanger sequencing, mutational analysis, and phylogenetic reconstruction. High-quality sequence data were obtained for six PB1 and eight PB2 gene fragments. Sequence analysis revealed a high degree of conservation within the PB1 gene, particularly across regions involved in viral replication, indicating strong evolutionary constraints. In contrast, the PB2 gene exhibited several amino acid substitutions, including changes at positions 464 and 678 in selected isolates. Notably, all analyzed strains lacked the mammalian adaptation marker E627K. Phylogenetic analysis clustered the Romanian isolates within Eurasian H5N1 lineages and demonstrated close genetic relationships with contemporary strains circulating in Eastern Europe and Russia. These findings highlight the genetic stability of PB1, the ongoing diversification of PB2, and the importance of continuous molecular surveillance for the early detection of viral variants with potential implications for host adaptation and zoonotic risk. Full article

(1) Background: Transboundary notifiable infectious viral diseases, such as lumpy skin disease (LSD), highly pathogenic avian influenza (HPAI), and foot-and-mouth disease (FMD), continue to severely disrupt Europe’s animal health and welfare, food security, and the multi-burdened livestock sector. (2) Methods: Through an extensive literature search, with data collected from the scientific literature, outbreak notifications, and European Union (EU) policy reports, this study synthesises evidence on the economic and societal impacts of preventive mass vaccination compared with stamping out for listed viral animal diseases in Europe. (3) Results: Evidence from LSD, HPAI, and FMD indicates that preventive vaccination reduces outbreak size, duration, and associated economic losses, particularly in high-risk and endemic settings. For LSD, vaccination is essential in eradication, as culling alone fails. For HPAI, evolving epidemiology supports vaccination-to-live strategies. In contrast, for FMD, despite epidemiological benefits of vaccination, the maintenance of FMD-free status without vaccination remains the dominant policy objective, constraining adoption of vaccination-to-live due to trade implications. (4) Conclusions: Overall, findings support the following recommendations: shifting toward preventive vaccination tailored by country and disease, prioritising vaccine-to-live strategies within a harmonised regulatory framework, and strengthening differentiating infected from vaccinated animals (DIVA)-based surveillance and trade-compatible frameworks, all sensible approaches to protect animal welfare and economic stability in Europe’s livestock sector. Full article

The H5N1 highly pathogenic avian influenza (HPAI) virus has caused severe global losses, reaching South America in 2022 and Antarctica in 2024. Here, we synthesize outbreak reports submitted to the World Organization for Animal Health by South American countries and overseas territories in this continent, and document the virus’s unprecedented expansion into Antarctica, affecting wild birds, wild mammals, and domestic poultry. Phylogenetic and time-calibrated Bayesian analyses were performed on available genomic sequences. Over 6 million domestic birds were lost, mostly from commercial operations. Of the 11 South American countries and overseas territories that reported H5N1 to WOAH, 10 reported infections in wild birds, spanning 104 species, 59.62% of which are migratory and predominantly non-trans-equatorial. Marine mammal outbreaks followed wild bird detections, with the South American sea lion (Otaria flavescens) being the most reported species. Several Antarctic bird species with migratory behavior were also reported in South America. Genomic analyses revealed multiple introduction events, regional viral diversification, and patterns consistent with repeated cross-species spillover events. These findings highlight H5N1’s extensive ecological reach in the Southern Hemisphere and underscore the urgent need for a One Health approach that strengthens wildlife and backyard-poultry surveillance, alongside coordinated regional action to control and prevent further HPAI spread. Full article

Highly pathogenic avian influenza (HPAI) A(H5N1) viruses of clade 2.3.4.4b have recently spread across the Americas, prompting intensified surveillance efforts in Brazil aimed at early detection in wild birds. As part of these efforts, we identified a low pathogenic avian influenza A(H11N2) virus in a white-rumped sandpiper (Calidris fuscicollis) sampled at Lagoa do Peixe National Park (PNLP) in southern Brazil. Whole-genome sequencing revealed that seven of the eight gene segments shared high nucleotide similarity (approximately 98.8%) with viruses previously detected in shorebirds from Delaware Bay, North America. In contrast, the PB1 segment showed high nucleotide similarity (approximately 99%) to the PB1 lineage associated with clade 2.3.4.4b A(H5N1) genotype B3.2 viruses circulating in the Americas. Phylogenetic, nucleotide identity, and molecular clock analyses indicated that this lineage shares a recent common ancestor with North American LPAI viruses and was subsequently detected in distinct viral genetic backgrounds. Although no HPAI virus was identified in this study, the presence of a PB1 segment related to H5N1-associated lineages suggests that genetic components linked to these viruses were circulating among low pathogenic avian influenza viruses in South America. These findings highlight the importance of continued surveillance in migratory bird populations to improve understanding of avian influenza virus diversity and support epidemiological monitoring. Full article