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Showing posts from December 19, 2025

Highly Pathogenic Avian #Influenza: #Tracking the #Progression from IAV #H5N1 to IAV #H7N9 and Preparing for Emerging Challenges

  Abstract Highly Pathogenic Avian Influenza (HPAI) viruses, particularly IAV (H5N1), continue to pose a major global threat due to their widespread circulation and high mortality rates in birds. Management of HPAI is complicated by challenges in conserving migratory bird populations, sustaining poultry production, and uncertainties in disease dynamics. Structured decision-making frameworks , such as those based on the PrOACT model, are recommended to improve outbreak response and guide critical actions , especially when HPAI virus (HPAIV) detections occur in sensitive areas like wildlife refuges . Surveillance data from late 2024 to early 2025 show persistent HPAI activity , with 743 detections across 22 European countries and beyond, and notable outbreaks in poultry in nations like Hungary, Iceland, and the UK . The proximity of poultry farms to water sources increases environmental contamination risks. Meanwhile, HPAI A(IAV (H5N1)) and other H5Nx viruses have been detected in a ...

#USA, #Wastewater Data for Avian #Influenza #H5 (#CDC, Dec. 19 '25)

  {Excerpt} Time Period: December 07, 2025 - December 13, 2025 {*} -- H5 Detection :   3 site(s) ( 0.7% ) -- No Detection :  451 site(s) ( 99.3% ) -- No samples in last week :  37 site(s) {*} Note: The H5 detection at site 2030 in Virginia is a result of a data error and is a false detection. This will be corrected in the next update. (...) Source:  Link:  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

#Sweden - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

{Höör Region} A farm with parent poultry. All animals were euthanized 18 December. A protection zone (3 km) and a surveillance zone (10 km) have been put in place around the infected farm and all other restrictions and necessary measures according to Regulation (EU) 2016/429 and EU DR 2020/687 are applied. Source:  Link:  https://wahis.woah.org/#/in-review/7136 ____

#Poland - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

  A poultry farm in Łódzkie Region. Source:  Link:  https://wahis.woah.org/#/in-review/7137 ____

A #pandemic #toolbox for clade 2.3.4.4b #H5N1 #influenza virus #risk #assessment

  {Excerpt} Since 1997, more than 1000 cases of highly pathogenic avian influenza A(H5N1) have been reported in humans . During this time, A(H5N1) viruses have evolved into dozens of clades , showing ever-expanding phylogenetic diversification and geographical spread . Over the past 5 years, clade 2.3.4.4b A(H5N1) viruses have exhibited rapid global expansion in migratory birds, with spillover to an increasing range of marine and terrestrial mammalian species . Among these species are dairy cattle , not previously recognised as a permissive host for influenza A viruses (IAV), leading to widespread clade 2.3.4.4b A(H5N1) outbreaks in herds in the USA and sporadic human infections linked with exposure to infected animals since March 2024. While person-to-person transmission has not been detected in the USA, the increased geographical distribution of and susceptibility of mammalian hosts to clade 2.3.4.4b A(H5N1) viruses has brought to the forefront a need to assess the pandemic risk ...

Attachment and #replication of clade 2.3.4.4b #influenza #H5N1 viruses in #human respiratory #epithelium: an in-vitro study

  Summary Background Highly pathogenic avian influenza H5N1 viruses of the A/Goose/Guangdong/1/1996 lineage pose a global threat to wildlife, domestic animals, and humans . Cross-species transmission events to mammals, including humans , in the past 4 years highlight this threat. For influenza A viruses, crucial determinants of cross-species and intraspecies transmission to and among mammals include attachment to and replication in respiratory airway epithelial cells . Although these determinants have been studied for H5N1 viruses in the past, limited studies for clade 2.3.4.4b viruses exist. Therefore, the aim of this study was to determine the ability of recent clade 2.3.4.4b H5N1 viruses to attach to human respiratory tissues, to replicate in human airway epithelial cells and the associated immune response. Methods In this in-vitro study, we investigated three H5N1 clade 2.3.4.4b viruses (H5N1Gull2022, H5N1Polecat2022, and H5N1Bovine2024) in comparison with previously studied 2....