ETIDIOH - NEW

  Abstract B etween 2022 and 2025, highly pathogenic avian influenza viruses (HPAIVs) of clade 2.3.4.4b, including four distinct H5 Eurasian (EA) genotypes , were detected in wild birds and mammals in the Svalbard Archipelago and on the island of Jan Mayen . We describe their epidemiology and genomic characteristics to improve understanding of HPAIV occurrence and transmission in the High Arctic . The initial cases in 2022 occurred during summer and involved a glaucous gull (Larus hyperboreus) and great skuas (Stercorarius skua) on Svalbard and Jan Mayen , representing the first detections of HPAIVs in the High Arctic . Three HPAIV genotypes were identified: EA-2020-C (H5N1), EA-2021-AB (H5N1), and EA-2021-I ( H5N5 ). In 2023 , HPAIVs were detected in a broader range of bird species, and retrospectively in an Atlantic walrus reported by another research group (Odobenus rosmarus rosmarus). Genotypes identified in 2023 were EA-2020-C (H5N1), EA-2021-I ( H5N5 ), and EA-2022-BB (H5N1)....

  Influenza at the human-animal interface  Summary and risk assessment, from 6 November to 19 December 2025 {1} -- New human cases {1,2}:  - From 6 November to 19 December 2025, based on reporting date , the detection of influenza A( H5N1 ) in one human , A( H5N5 ) in one human , A( H9N2 ) in seven humans , and an influenza A( H1N1 ) variant virus in one human were reported officially.  - In addition , one human case of infection with an influenza A( H1N2 ) variant virus was detected.  -- 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}  - Additionally, low pathogenicity avian influenza viruses as well a...

  5 December 2025 Situation at a glance On 15 November 2025, WHO was notified of the 71st confirmed human case with influenza A(H5) since early 2024 in the United States of America — the first human case reported in the United States of America since February 2025 .  On 20 November, U.S. Centers for Disease Control and Prevention (CDC) laboratory sequencing verified the virus as influenza A(H5N5), representing the first globally reported human case caused by an influenza A(H5N5) virus.  The investigation by health authorities in the United States of America is ongoing.  Contact tracing identified no further cases amongst contacts, and there is currently no evidence of human-to-human transmission .  Due to the constantly evolving nature of influenza viruses , WHO continues to stress the importance of global surveillance to detect and monitor virological (including genomics), epidemiological and clinical changes associated with emerging or circulating influenza vi...

  {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...

  The person was infected with the H5N5 virus; the risk to the public remains low OLYMPIA – A Grays Harbor County resident who was undergoing treatment for H5N5 avian influenza died today .  The Washington State Department of Health offers its heartfelt condolences to the person’s family and friends. The person was an older adult with underlying health conditions .  Out of respect for the family’s privacy , we are not releasing their name, gender, or age.  The person had been hospitalized in King County since early November. Testing at the UW Medicine Clinical Virology Lab identified the virus as H5N5 , making this the first recorded infection with this variant in a person globally.  The result was confirmed by the Centers for Disease Control and Prevention (CDC). The risk to the public remains low .  No other people involved have tested positive for avian influenza.  Public health officials will continue to monitor anyone who was in close contact with...

  {Excerpt} Novel Influenza A Virus Infections Two confirmed human infections with novel influenza A viruses were reported to CDC this week .  One infection with an influenza A(H5N5) virus was reported by the Washington State Department of Health and one infection with an influenza A(H1N2) variant (A(H1N2)v) virus was reported by the Vermont Department of Health. One infection with an influenza A(H5N5) virus was reported by the Washington State Department of Public Health .  -- The case occurred in an individual aged ≥18 years .  -- This individual developed symptoms during the week ending October 25 , 2025 (Week 43) and was hospitalized with their illness during the week ending November 8, 2025 (Week 45).  -- Respiratory specimens collected at the healthcare facility tested positive for influenza A and were presumptive positive for influenza A(H5) at the University of Washington.  -- The specimens were sent to the Washington State Public Health Laboratory ...