ETIDIOH - NEW

ABSTRACT The highly pathogenic avian influenza virus A(H5N1) clade 2.3.4.4b has caused a human outbreak in North America since March 2024 . Here, we conducted a serosurveillance study to determine the risk of A(H5N1) clade 2.3.4.4b (2024 cattle H5N1 ) to general population . In the initial screening of 180 serum specimens encompassing all age groups , 2.2% (4/180) had detectable neutralizing antibody (nAb) titers against 2024 cattle H5N1, with all collected from older adults aged ≥60 years old . Further screening showed that 5.0% (15/300) of adults aged ≥70 years old had detectable nAb titers against the 2024 cattle H5N1. All serum specimens with nAb titer of ≥40 had detectable HI titer, and there was a positive correlation between nAb titer and HA binding (r=0.3311, 95% confidence interval 0.2264 to 0.4283; P<0.0001). The nAb titer against seasonal H1N1 virus was 3.9-fold higher for patients with detectable H5N1 nAb than those without (geometric mean titer: 108.5 [95% CI 56.3-209.1...

Abstract The H9N2 subtype of avian influenza viruses (AIVs) is widely prevalent in poultry and wild birds globally , with occasional transmission to humans . In comparison to other H9N2 lineages, the BJ/94 lineage has raised more public health concerns; however, its evolutionary dynamics and transmission patterns remain poorly understood. In this study, we demonstrate that over three decades (1994–2023), BJ/94 lineage has undergone substantial expansion in its geographical distribution , interspecies transmission , and viral reassortment with other AIV subtypes, increasing associated public health risks . These changes were primarily driven by the emergence of a dominant genotype G57. In the first decade, G57 emerged in East China and rapidly adapted to chickens and spread across China . Since 2013, the G57 genotype has expanded beyond China into eight other countries and reassorted with various AIV subtypes to form new zoonotic reassortants . Chickens have played a key role in the gen...

 A poultry farm in Bayern Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6131 _____