ETIDIOH - NEW

  Abstract Background   Infection of backyard and poultry with low pathogenicity avian influenza LPAI A(H5N2) viruses has occurred in Mexico since 1994, and the first human infection caused by this influenza virus was detected in 2024 . Since its emergence in the Americas , frequent reassortments between high pathogenicity avian influenza HPAI A(H5N1) and LPAI viruses has occurred. In September 2025 , the Instituto Nacional de Enfermedades Respiratorias of Mexico City identified an unsubtypeable influenza A virus infection in a young adult patient later determined to be a reassortant HPAI (H5N2) virus with a clade 2.3.4.4b HA .  Methods   We analyzed clinical and epidemiologic data from this patient. Respiratory samples were tested for influenza RT-qPCR assays . Genomic sequence and phylogenetics analyses were performed to provisionally assign a new genotype to the novel HPAI A(H5N2) reassortant virus.  Results   The patient presented with fever and tachypn...

  {Summary} Confirmed Cases at National Level [National - Total Cases : 71 { +1 }{§}] [Cases -  Exposure Source] -- 41 - Dairy Herds (Cattle){*} -- 24 - Poultry Farms and Culling Operations {*} -- 3 - Other Animal Exposure {†} -- 3 - Exposure Source Unknown {‡} Probable Cases at National Level [National - Total Cases : 7 {no change} ] [Cases -  Exposure Source] -- 1 - Dairy Herds (Cattle) {*} -- 5 - Poultry Farms and Culling Operations {*} --  0 - Other Animal Exposure {†} -- 1 - Exposure Source Unknown {‡} NOTE : One additional case was previously detected in a poultry worker in Colorado in 2022. Louisiana reported the first H5 bird flu death in the U.S. {*} Exposure Associated with Commercial Agriculture and Related Operations {†} Exposure was related to other animals such as backyard flocks, wild birds, or other mammals {‡} Exposure source was not able to be identified (...) {§} A case from Washington State, see more at:  https://doh.wa.gov/newsroom/grays-h...

  Abstract Three critically ill or fatal avian influenza A(H5N1) human infections have been reported in North America since November 2024 . Notably, all were infected with genotype D1.1 instead of B3.13, the dominant genotype before November 2024. Here, we demonstrated that D1.1 could replicate to higher titers in human nasal and airway organoid-derived transwell monolayers from 6 donors . D1.1 exhibited a better binding to α2,3- and α2,6-linked SA than B3.13. No significant differences in most inflammatory or antiviral cytokines/chemokines was observed. These observations suggest that D1.1 is better adapted to both the upper and lower human respiratory tract epithelium than B3.13. Source:  Link:  https://academic.oup.com/jid/advance-article/doi/10.1093/infdis/jiaf598/8341570#google_vignette ____

  Abstract The evolutionary divergence of the A(H5) hemagglutinin (HA) gene of high pathogenicity avian influenza (HPAI) viruses (A/goose/Guangdong/96 lineage) was analyzed by phylogenetic and average pairwise distance methods to identify clades that merit nomenclature updates . Based on this assessment, 12 new clade designations were recommended based on division of clade 2.3.2.1c and 2.3.4.4 viruses, which were reported in Africa, Antarctica, Asia, Europe, the Middle East, the Americas and Oceania since the most recent WHO/WOAH/FAO H5 Evolution Working Group update. Competing Interest Statement The authors have declared no competing interest. Source:  Link:  https://www.biorxiv.org/content/10.1101/2025.11.23.690055v1 ____

  A poultry farm in Opolskie Region. Source:  Link:  https://wahis.woah.org/#/in-review/7037 ____

  {Summary} Time Period: November 09, 2025 - November 15, 2025 -- H5 Detection :  1 site(s) ( 0.3% ) -- No Detection :  382 site(s) ( 99.7% ) -- No samples in last week :  75 site(s) (...) Source:  Link:  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

Wild Species (unspecified) in Xinjiang Uygur Region. Source:  Link:  https://wahis.woah.org/#/in-review/6978 ____

  A poultry farm in Oberösterreich Region. Source:  Link:  https://wahis.woah.org/#/in-review/7024 ____

  • New human cases {1,2}:  -- From 30 September to 5 November 2025 , based on reporting date, the detection of influenza A(H5N1) in one human , A( H5N2 ) in one human and 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 in the above human infection 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...

A slaughter turkeys operation in Kujawsko-Pomorskie Region. Source: WOAH,  https://wahis.woah.org/#/in-review/7012 ____

  {Hessen Region} laying hens (500), broilers (200), ducks for fattening (200), geese for fattening (700), turkeys for fattening (500) Source: WOAH,  https://wahis.woah.org/#/in-review/7021 ____

  Phnom Penh, November 16 (Xinhua) -- Cambodia's Ministry of Health confirmed on the 16th that a young man residing in Phnom Penh had died from avian influenza (H5N1). Authorities urged the public to be vigilant and take effective preventative measures. According to the report, the 22-year-old man experienced severe symptoms including fever, cough, shortness of breath, and difficulty breathing . Despite the medical team's best efforts, his condition rapidly deteriorated, and he died on the 15th of this month . This is the first reported human death from avian influenza in the country's capital this year. Following the incident, the Cambodian Ministry of Health immediately activated its emergency response mechanism . Local professional teams are conducting a comprehensive and detailed epidemiological investigation to trace the source of infection and identify close contacts . To prevent further spread of the epidemic in the community, authorities have urgently allocated and ...

  A 22-year-old Cambodian man died of H5N1 bird flu , the Ministry of Health said in a statement released Sunday, November 16, 2025, as reported by Xinhua and quoted by Antara. "Laboratory results from the Cambodian National Institute of Public Health on November 15, 2025 , showed that the man was positive for H5N1 virus infection," the Cambodian Ministry of Health said in a statement. (...) Source: Tempo,  https://www.tempo.co/internasional/pria-kamboja-tewas-akibat-flu-burung-h5n1-2090146 ____

  {Excerpt} National situation summary Person-to-person spread :  None -- There is no known person-to-person spread at this time. Current public health risk :  Low -- The current public health risk is Low. Cases in the U.S. :  71 cases Deaths in U.S. :  1 death (...) Situation summary of confirmed and probable human cases since 2024 {Confirmed Cases}:  -- National: Total Cases: 71 {+1} [Cases - Exposure Source] -- 41 - Dairy Herds (Cattle){*} -- 24 - Poultry Farms and Culling Operations{*} -- 3 - Other Animal Exposure{†} -- 3 - Exposure Source Unknown{‡} {Probable Cases}:  -- National: Total Cases: 7 [Cases - Exposure Source] -- 1 - Dairy Herds (Cattle){*} -- 5 - Poultry Farms and Culling Operations{*} -- 0 - Other Animal Exposure{†} -- 1 - Exposure Source Unknown{‡} NOTE : One additional case was previously detected in a poultry worker in Colorado in 2022. Louisiana reported the first H5 bird flu death in the U.S. {*} Exposure Associated with Comm...

  {Scotland} Broiler breeder flock of 28-week-old birds. Increased mortality and other clinical signs reported. Samples taken were found positive for HPAI H5N1. Source: WOAH,  https://wahis.woah.org/#/in-review/7013 ____

Human Avian Influenza Cases in Washington State Residents {*} [Exposure - Probable - Confirmed - Total human cases (H5)] -- Poultry - 3 - 11 - 14 -- Unknown - 1{^} - 0 - 1 -- Total - 15 {*} Washington residency could not be confirmed for one case with exposure to poultry in Washington. {^} Currently under investigation; case classification and source of infection may be updated. Note : Updates to national public health reporting and notification of novel influenza A infections were approved by the Council of State and Territorial Epidemiologists (CSTE) in June 2024 and enacted in September 2024. Whether a case is counted as confirmed or probable is determined after completion of a public health case investigation and takes into account a person's exposure to avian influenza virus, whether confirmatory testing at the CDC was negative or positive, and whether a person experienced symptoms of illness. The specific criteria used to determine if a case is confirmed, or probable is based...

For immediate release: November 13, 2025   (25-136) Contact: DOH Communications If confirmed, this would be the first human case of avian influenza reported in Washington in 2025 OLYMPIA – A Grays Harbor County resident has tested preliminarily positive for avian influenza, also known as bird flu . Confirmatory testing through the Washington State Public Health Laboratories is pending. Health officials are working to determine the potential sources of the infection , including contact with wild or domestic birds .  The person, who is an older adult with underlying health conditions, developed a high fever, confusion, and respiratory distress and was hospitalized in early November.  They are currently receiving treatment in King County after previously being treated in Thurston and Grays Harbor counties. Public health disease experts have not identified any risk to the public . The Washington State Department of Health is working with the local health departments and ...

  A Slaughter geese operation in Mazowieckie Region. Source: WOAH,  https://wahis.woah.org/#/in-review/7008 ____

  Highlights •  Human antibody HB420 cross-reacts with neuraminidases from H3N2 and H5N1 •  HB420 engages the neuraminidase active site via a single Asp residue •  Germline HB420 is N2 specific but gains reactivity to N1 through somatic mutation •  HB420 provides in vivo protection against both H3N2 and H5N1 Summary The ongoing spread of highly pathogenic avian influenza H5N1 clade 2.3.4.4b virus in animals and its occasional spillover to humans have raised concerns about a potential H5N1 pandemic . Although recent studies have shown that pre-existing human antibodies can recognize H5N1 neuraminidase , the molecular basis of how this cross-reactivity develops remains poorly understood. In this study, we used a phage display antibody library derived from 245 healthy donors to isolate an antibody, HB420, that cross-reacts with neuraminidases of human H3N2 and avian H5N1 clade 2.3.4.4b viruses and confers protection in vivo. Cryogenic electron microscopy analysis r...

  Suspicion of avian influenza was raised at the Mirovice slaughterhouse. The suspicion concerned slaughtered ducks originating from a commercial fattening duck farm (Primary outbreak No. HPAI1-2/2025). A suspicion of HPAI was raised based on the pathological-anatomical findings and the information that there has been increased mortality in the farm. The official veterinary officer collected samples of ducks from the slaughterhouse for testing, which were sent by courier to the National Reference Laboratory, and issued preliminary veterinary measures for the slaughterhouse to prevent the spread of the disease. In connection with the suspicion of HPAI at the slaughterhouse (Secondary outbreak No. HPAI1-3/2025), commercial poultry farm with a fattening ducks. During the on-site inspection, it was found that the animals were dying massively (in total 2 700 birds and the high mortality still ongoing) and showing clinical signs (lethargy, ruffled feathers, and neurological symptoms). Th...