ETIDIOH - NEW

  New human cases {1,2}:  -- From 2 July to 25 August 2025 , based on reporting date, the detection of influenza A( H5N1 ) in five humans and influenza A(H9N2) in two humans were reported officially.   Circulation of influenza viruses with zoonotic potential in animals :  - High pathogenicity avian influenza (HPAI) events in poultry and non-poultry animal species continue to be reported to the World Organisation for Animal Health (WOAH).{3}  - The Food and Agriculture Organization of the United Nations (FAO) also provides a global update on avian influenza viruses with pandemic potential.{4}  Risk assessment {5}:  - Sustained human to human transmission has not been reported from these events.  - Based on information available at the time of this risk assessment update , the overall public health risk from currently known influenza A viruses detected at the human-animal interface has not changed and remains low .  - The occurrence of sus...

Ducks for fattening (1800), geese for fattening (100) in Mecklenburg-Vorpommern Region. Laying hens (150). ducks for fattening (2800), geese for fattening (2900) in Mecklenburg-Vorpommern Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6780 ____

  Abstract Highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b viruses have infected >1,000 herds of dairy cattle and hundreds of poultry flocks in the United States since the beginning of 2024. Seventy human cases have been reported during that period, mainly through occupational exposure . Although prior influenza A(H1N1)pdm09 virus infection has been shown to confer protection against influenza A(H5N1) clade 2.3.4.4b virus infection in the ferret model, it remains unclear if influenza vaccines , known to elicit a less potent and narrower cross-reactive immune response, can achieve a similar effect. In this article, we demonstrate that immunization with commercially available human seasonal influenza vaccines also confers partial protection against disease caused by H5N1 clade 2.3.4.4b virus in ferrets , which is partially associated with the presence of cross-reactive antibodies targeting H5N1 virus antigens. Source: US Centers for Disease Control and Prevention,  h...

  09/09/2025 -  Foz do Iguaçu, Brazil  In an unprecedented response to the rapid global spread of high pathogenicity avian influenza (HPAI), stakeholders and experts from across the poultry sector, public health, science, and policy spheres have convened in Brazil in a landmark meeting .  This first-ever global multisectoral dialogue aims to forge coordinated defense against the escalating threat to animal and human health and agricultural livelihoods. Avian influenza, commonly known as bird flu , is a highly contagious viral disease that primarily infects birds. The virus belongs to the Type A influenza family, which is known for its ability to mutate and change rapidly. Since 2020, HPAI has expanded rapidly across continents , devastating poultry flocks , impacting biodiversity , trade and food security , and raising concerns over its potential to spark a human pandemic . The currently circulating avian influenza panzootic is now widespread, and represents one of t...

  {Summary} Time Period: August 31, 2025 - September 06, 2025 -- H5 Detection :  4 sites ( 0.9% ) -- No Detection :  418 sites ( 99.1% ) -- No samples in last week :  43 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

  Abstract Since 2021, the panzootic of high pathogenicity avian influenza (HPAI) represents an increasing threat to wild vertebrate populations . In this context, recent vaccines developed for poultry could provide tools for the conservation of wild endangered birds populations . The king penguin (Aptenodytes patagonicus), a long-lived seabird breeding in dense colonies with an extended chick-rearing period , was identified as a possible surrogate species for a vaccination trial in a sub-Antarctic natural setting . We investigate here the immune response of king penguin chicks to a self-amplifying mRNA vaccine against a H5 HPAI clade 2.3.4.4b protein. Thirty chicks were vaccinated (primo- and boost-injections), 20 were kept as controls. Along 250 days of monitoring, vaccinated chicks showed a high and persistent immune response , granting a strong seroneutralisation capacity against the virus, up to fledging. No adverse effects were observed. The screening for antibodies against u...

  Abstract Our study has for the first time identified H5N1 strains (clade 2.3.4.4b, genotype B3.2) in brown skuas from the Fildes Peninsula , South Shetland Islands, Antarctica . These findings indicate that highly pathogenic avian influenza H5N1 viruses is now actively circulating in Antarctic ecosystems , representing a significant expansion of its geographic range. Competing Interest Statement The authors have declared no competing interest. Funder Information Declared National Key Research and Development Program of China, 2024YFC2813605, 2023YFC2605504 Source: BioRxIV,  https://www.biorxiv.org/content/10.1101/2025.09.06.674605v1 ____

  Abstract Understanding the mechanisms underlying the emergence and spread of high pathogenicity avian influenza virus (HPAIV) is critical for tracking its global dissemination , particularly via migratory seabirds , given their role in transmission over long distances . Scavenging seabirds, such as skuas , may act as both reservoirs and vectors , and have been linked to multiple outbreaks since 2021. Here, we report the detection of HPAIV clade 2.3.4.4b H5N1 in three Tristan skua (Stercorarius antarcticus hamiltoni) carcasses on Gough Island in the central South Atlantic Ocean . To investigate potential incursion routes, we combined genomic analyses with year-round tracking data from global location sensors . Although migratory movement patterns suggested southern Africa as the most obvious pathway, the strain detected on Gough Island was more closely related to that found in South Georgia , suggesting infection may have occurred during the pre-laying exodus when skuas disperse i...

{Automatic translation from Chinese, edited} [Xinhua News Agency Micro Special] Due to the outbreak of avian influenza in many places, the Andalusia Autonomous Region in southern Spain has temporarily closed a number of parks and other attractions in recent days, including two attractions included in the UNESCO World Heritage List , and the infected animals have been killed at relevant locations. According to AFP, Seville City Hall announced on social media on the 11th that the Maria Luisa Park in the city center was closed due to the discovery of dead birds . The park will clean up the dead animals and disinfect them. The city recently closed three other parks where dead birds were found, including a World Heritage site. Catalina Garcia, an environmental official for the Andalusian autonomous region, said on social media that three outbreaks of avian influenza were detected in wild birds in Doñana National Park , a World Heritage site, and the affected birds were culled. The national ...

  Abstract We detected H5N1 high pathogenicity avian influenza in captive Greater Rhea (Rhea americana). Viral genetic analysis revealed the mammalian associated PB2-E627K mutation , indicating selection of mammalian-relevant mutations in ratites . Pathologic investigation of available tissues demonstrated severe multifocal necrotising inflammation , and a strong vasculotropism. Competing Interest Statement The authors have declared no competing interest. Source: BioRxIV,  https://www.biorxiv.org/content/10.1101/2025.09.08.674895v1 ____

  A poultry farm in Nordland Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6767 ____

  Highlights •  The H5N1 influenza virus-like particle vaccines are prepared through baculovirus expression vector system. • In vitro assessments have confirmed that this VLP vaccine has the correct conformation and functional activity. • This VLP vaccine induces robust humoral and cellular immune responses in mice , and provides complete protection against infection with the matched strain. Abstract Avian influenza virus infections pose a potential pandemic threat . The currently licensed vaccines have inherent limitations, emphasizing the urgent need for improved influenza vaccines. Here, we developed a novel hemagglutinin (HA) virus-like particle (VLP) vaccine candidate through the baculovirus expression vector system (BEVS). The engineered VLPs incorporate HA from H5N1 and matrix 1 (M1) protein from H1N1 . Comprehensive characterization revealed that purified HA VLPs exhibited morphological fidelity to native influenza virions while maintaining key viral biological propert...

  Abstract Highly pathogenic avian influenza virus of the H5N1 subtype has been infecting U.S dairy cattle and spreading among dairy farms since March 2024 . H5N1 surveillance systems for dairy farms are needed, but information on whether environmental sampling can inform these systems is lacking. To guide a surveillance framework , we determined the environmental locations on H5N1-affected dairies (n = 25) in four states (California, Colorado, Michigan, and Ohio) that harbored influenza A virus (IAV), and explored sample characteristics that may influence viral detection. A total of 623 samples from environments and sale barns were characterized for IAV and classified into six categories based on location. A total of 94 samples ( 15.1% ) had IAV detected , the majority in the following categories: milking equipment/personal protective equipment , parlor surfaces , and wastewater/lagoons/manure . These results suggest that dairy environments most likely to harbor IAV are those with...

  Abstract Understanding the transmission routes of high-pathogenicity avian influenza (HPAI) is crucial for developing effective control measures to prevent its spread . In this context, windborne transmission , the idea that the virus could travel through the air over considerable distances, is a contentious concept, and documented cases have been rare. Here, though, we provide genetic evidence supporting the feasibility of windborne transmission . During the 2023−24 HPAI season , molecular surveillance identified identical H5N1 strains among a cluster of unrelated commercial farms about 8 km apart in the Czech Republic . The episode started with the abrupt mortality of fattening ducks on one farm. This was followed by disease outbreaks at two nearby high-biosecurity chicken farms . Using genetic, epizootiological, meteorological and geographical data, we reconstructed a mosaic of events strongly suggesting wind was the most probable mechanism of infection transmission between po...

{Summary} Time Period: August 24, 2025 - August 30, 2025 -- H5 Detection :  3 sites ( 0.7% ) -- No Detection :  428 sites ( 99.3% ) -- No samples in last week :  31 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

  Abstract H5N1 highly pathogenic avian influenza viruses have spread globally and pose a risk for a human pandemic . Prior studies suggest that early life exposures to group 1 influenza viruses (H1N1 and H2N2) prime antibodies that cross-react to the hemagglutinin of H5N1 , which is also a group 1 virus. Less is known about how immune history affects antibody responses against the neuraminidase (NA) of H5N1 viruses. Here, we measured NA inhibition antibodies against multiple H5N1 viruses using sera from 155 individuals born between 1927 and 2016 . We found that individuals primed in childhood with H1N1 viruses were more likely to possess higher levels of antibodies that cross-react with the NA of H5N1 viruses compared to individuals primed in childhood with H2N2 or H3N2 viruses. While young children rarely possessed cross-reactive NA antibodies, we found that childhood infections with contemporary H1N1 , but not H3N2, viruses can elicit them. These data suggest that immune history...

  Summary -- What is already known about this topic? - As of January 1, 2025, 37 human cases of highly pathogenic avian influenza (HPAI) A( H5N1 ) had been detected in California , none of which occurred in San Francisco. -- What is added by this report? - On January 9, 2025, a case of HPAI A(H5N1) infection was identified in a school-aged child in San Francisco through enhanced surveillance (influenza A virus subtyping of a sample of specimens weekly). No source of exposure was identified, and investigations found no laboratory evidence of human-to-human transmission among close contacts. -- What are the implications for public health practice? - Enhanced surveillance and timely subtyping of a subset of influenza A–positive specimens, including specimens from persons without known A(H5N1) exposure, are important to detect avian influenza A virus infections. Public health investigations are critical to monitoring for human-to-human transmission. Abstract In response to a highly pat...

  Neurological-respiratory disease in backyard domestic birds raised in a farm with partial laboratory results of H5 avian influenza virus . Zoning was implemented for the control of the outbreak with stamping out measures for all affected and contact birds on the farm, and surveillance will be carried out in the perifocal and protection areas. A body of water representing a possible place of contact between domestic and wild birds is located on the premises. Source: WOAH,  https://wahis.woah.org/#/in-review/6755 ____

  A poultry farm in Santarém Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6759 ____

  A poultry farm in Schleswig-Holstein State. Source: WOAH,  https://wahis.woah.org/#/in-review/6760 ____