ETIDIOH - NEW

  New human cases {2}:  -- From 28 May to 1 July 2025 , based on reporting date, the detection of influenza A( H5N1 ) in nine humans , influenza A( H9N2 ) in three humans and influenza A( H10N3 ) in one human were reported officially. Additionally, one human case of infection with an influenza A(H5N1) virus was detected.  Circulation of influenza viruses with zoonotic potential in animals :  -- High pathogenicity avian influenza (HPAI) events in poultry and non-poultry 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 the risk assessment, the overall public health risk from currently known influenza viruses circulating at t...

{Excerpt} 1. Background   A risk assessment exercise using the Tool for Influenza Pandemic Risk Assessment ( TIPRA ) was conducted for Clade 2.3.4.4b A(H5N1) genotype B3.13 virus in Aug – Oct 2024 .   From late 2023, unexplained illnesses were reported in dairy cattle across multiple states in the United States .  Following those events , detection of avian influenza A(H5N1) in dairy cattle from Texas was confirmed on 25 March 2024.  As of 9 December 2024 , the virus has been detected in 720 dairy cattle herds across 15 states, according to the United States Department of Agriculture (USDA), with a total of 47 human infections from poultry and dairy cattle sources, excluding 11 human cases from Washington state , that might belong to genotype D1.1, also reported.  Wild and domestic animals (e.g., cats, raccoons) near infected herds have been affected as well.  The outbreak remains uncontrolled .  Due to the unprecedented spread of the virus among ...

Abstract The emergence of highly pathogenic avian influenza (HPAI) A(H5N1), clade 2.3.4.4b, genotype B3.13 in U.S. dairy cattle marks a significant shift in the virus' host range and epidemiological profile. Infected cattle typically exhibit mild clinical signs, such as reduced milk production, mastitis and fever, with morbidity generally below 20% and mortality averaging 2%. Transmission within farms is primarily driven by contaminated milk and milking procedures , while farm‐to‐farm spread is mainly linked to cattle movement and shared equipment . The virus demonstrates high replication in mammary glands , with infected cows shedding large quantities of virus in milk for up to 3 weeks, even in the absence of clinical signs. Shedding through other routes appears limited. Infected cattle develop virus‐specific antibodies within 7–10 days , offering short‐term protection, though the duration and robustness of immunity remain unclear. Between March 2024 and May 2025, the virus was co...

ABSTRACT H1 and H3 influenza A viruses (IAVs) circulating in European pigs are markedly distinct from those circulating in other global swine populations . These viruses exhibit significant genetic diversity , further expanded by periodic interspecies transmission of IAVs from humans into pigs , followed by sustained circulation. Several zoonotic IAV infections in humans in Europe have been associated with the 1C lineage of H1 IAVs . Given the predominance of H1 detections in pigs and their zoonotic potential, we quantified antigenic evolution of H1 viruses in European pigs using ferret and pig models and assessed diversity relative to swine IAV vaccine strains. Ferret and swine antisera comparisons revealed no significant differences in antibody responses . Viruses of the 1A.3.3.2 clade exhibited reduced cross-reactivity to human seasonal vaccine strains from 2009. Viruses of the 1B.1.2.2 clade showed no cross-reactivity to the 1978 human seasonal influenza viruses nor to candidate va...

  New human cases {2}:  -- From 23 April to 27 May 2025, based on reporting date, the detection of influenza A( H5N1 ) in three humans, the detection of influenza A( H9N2 ) virus in eight humans and the detection of influenza A( H10N3 ) in one human were reported officially.  -- Circulation of influenza viruses with zoonotic potential in animals:  - High pathogenicity avian influenza (HPAI) outbreaks in poultry and non-poultry animals 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 these events. Based on information available at the time of the risk assessment , the overall public health risk from currently known influenza viruses circulating at the human-animal interface has not c...

  Situation at a glance Since mid-February 2025, according to data available from sentinel sites, global SARS-CoV-2 activity has been increasing, with the test positivity rate reaching 11%, levels that have not been observed since July 2024.  This rise is primarily observed in countries in the Eastern Mediterranean, South-East Asia, and Western Pacific regions .  Since early 2025 , global SARS-CoV-2 variant trends have slightly shifted. Circulation of LP.8.1 has been declining, and reporting of NB.1.8.1, a Variant Under Monitoring (VUM), is increasing , reaching 10.7% of global sequences reported as of mid-May.  Recent increases in SARS-CoV-2 activity are broadly consistent with levels observed during the same period last year, however, there still lacks a clear seasonality in SARS-CoV-2 circulation, and surveillance is limited.  Continued monitoring is essential . WHO advises all Member States to continue applying a risk-based, integrated approach to managing C...