ETIDIOH - NEW

  Abstract Highly pathogenic influenza A viruses of the H5 subtype continue to diversify worldwide through mutation and genetic reassortment , generating novel variants with unpredictable consequences under the One Health approach . Between 2024 and 2025 , five outbreaks of avian influenza A viruses were detected in backyard poultry across Michoacán, Estado de México , and Ciudad de México . We conducted molecular and genetic characterization of five highly pathogenic H5N2 viruses isolated from these events. All cases tested positive for influenza A virus and the H5 hemagglutinin , exhibiting high pathogenicity with intravenous pathogenicity index values ranging from 2.88 to 3.0. Whole-genome sequencing revealed novel reassortants containing hemagglutinin from Eurasian H5N1 clade 2.3.4.4b and neuraminidase from the endemic Mexican H5N2 lineage . The viral genome of the isolate from Michoacán contained six segments derived from Eurasian H5N1 viruses introduced into North America in ...

  February 2026  WHO convenes technical consultations {1} in February and September each year to recommend viruses for inclusion in influenza vaccines {2} for the northern hemisphere (NH) and southern hemisphere (SH) influenza seasons, respectively.  This recommendation relates to the influenza vaccines for use in the NH 2026-2027 influenza season .  A recommendation will be made in September 2026 relating to vaccines that will be used for the SH 2027 influenza season.  WHO guidance for choosing between the NH and SH formulations for countries in tropical and subtropical regions is available on the WHO Global Influenza Programme website {3}.   National or regional authorities approve the composition and formulation of influenza vaccines used in each country.  National public health authorities are responsible for making recommendations regarding the use of the vaccine.  WHO has published recommendations on the prevention of influenza {4}....

  A Barnacle goose was found diseased and was euthanized. It was sent to the Swedish Veterinary Agency for laboratory analysis as part of the national surveillance program for avian influenza. {Sölvesborg Region} Source:  Link:  https://wahis.woah.org/#/in-review/7191 ____

Mallards in Saldus Region.  Birds tested in frame of EFSA call project for Establishing capacities for active surveillance of highly pathogenic avian influenza in wild birds in Europe. Source:  Link:  https://wahis.woah.org/#/in-review/7187 ____

  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...

  • 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 wild Peregrine falcon in Kagoshima Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6545 ____

Abstract Background In late 2023, the first human case caused by an H10N5 avian influenza virus (AIV) was diagnosed in China . H10Ny AIVs have been identified in various poultry and wild birds in Eurasia, the Americas, and Oceania. Methods We analyzed the clinical data of the H10N5 AIV-infected patient, isolated the virus, and evaluated the virus receptor-binding properties together with the H10N8 and H10N3 AIVs identified in humans and poultry. The genomic data of the human-infecting H10N5 strain and avian H10Ny AIVs (n = 48, including 16 strains of H10N3 and 2 strains of H10N8) from live poultry markets in China , during 2019–2021, were sequenced. We inferred the genetic origin and spread pattern of the H10N5 AIV using the phylodynamic methods. In addition, given all available nucleotide sequences, the spatial-temporal dynamics, host distribution, and the maximum-likelihood phylogenies of global H10 AIVs were reconstructed. Findings The first H10N5 AIV-infected human case co-infected...

ABSTRACT Reassortant highly pathogenic avian influenza A(H5N2) clade 2.3.4.4.b viruses were detected from ducks and environmental samples in Egypt , June 2024. Genomic and phylogenetic analyses revealed a novel genotype produced by the reassortment of an A( H5N1 ) clade 2.3.3.4b virus with an A( H9N2 ) G1-like virus. Monitoring the spread of this virus is important. Source: Emerging Microbes and Infections,  https://www.tandfonline.com/doi/full/10.1080/22221751.2025.2455601#abstract _____

Abstract In April 2024, the Instituto Nacional de Enfermedades Respiratorias of Mexico City identified a case of unsubtypeable Influenza A in a 58-year-old immunocompromised patient with renal failure due to diabetic nephropathy and bacterial peritonitis. Through sequencing the M, NS, NA, NP, and HA complete segments, we identified an H5N2 influenza virus with identity of 99% with avian influenza A(H5N2) from Texcoco, Mexico, in 2024. This case is the first reported with direct evidence of human infection caused by the H5N2 influenza virus; the relationship of the virus with the severity of his condition remains unknown. Source: Viruses,  https://www.mdpi.com/1999-4915/17/2/205 _____

Backyard reared poultry in Camarines Norte Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6167 ______