Evolution of Avian Influenza Virus (H3) with Spillover into Humans, China

• DOI: 10.3201/eid2906.221786
• Publication Date: 2023-05-16T17:52:41Z
• Authors: Jiaying Yang; Ye Zhang; Lei Yang; Xiyan Li; Hong Bo; Jia Liu; Min Tan; Wenfei Zhu; Yuelong Shu; Dayan Wang
• Keywords: Reassortment; Pandemic

The continuous evolution of avian influenza viruses (AIVs) subtype H3 in China and the emergence human infection with AIV H3N8 highlight their threat to public health. Through surveillance poultry-associated environments during 2009-2022, we isolated sequenced 188 AIVs across China. Performing large-scale sequence analysis publicly available data, identified 4 sublineages established domestic ducks via multiple introductions from wild birds Eurasia. Using full-genome analysis, 126 distinct genotypes, which H3N2 G23 genotype predominated recently. G25 viruses, spilled over humans, might have been generated by reassortment between G23, bird H3N8, poultry H9N2 before February 2021. Mammal-adapted drug-resistance substitutions occasionally occurred AIVs. Ongoing for risk assessment are imperative potential pandemic preparedness.