Genetics of H5N1 and H5N8 High-Pathogenicity Avian Influenza Viruses Isolated in Japan in Winter 2021–2022

• Published in: Viruses
• Main Authors: Junki Mine, Yoshihiro Takadate, Asuka Kumagai, Saki Sakuma, Ryota Tsunekuni, Kohtaro Miyazawa, Yuko Uchida
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2024
• Subjects: avian flu; high pathogenicity avian influenza virus; Japan; 2021/2022 season; phylogenetic analysis; Microbiology; QR1-502; Avian flu; Siberia
• Online Access: https://doi.org/10.3390/v16030358; https://doaj.org/article/6e6d070e8f08433eb73204f40f4e9d8e

In winter 2021–2022, H5N1 and H5N8 high-pathogenicity avian influenza (HPAI) viruses (HPAIVs) caused serious outbreaks in Japan: 25 outbreaks of HPAI at poultry farms and 107 cases in wild birds or in the environment. Phylogenetic analyses divided H5 HPAIVs isolated in Japan in the winter of 2021–2022 into three groups—G2a, G2b, and G2d—which were disseminated at different locations and times. Full-genome sequencing analyses of these HPAIVs revealed a strong relationship of multiple genes between Japan and Siberia, suggesting that they arose from reassortment events with avian influenza viruses (AIVs) in Siberia. The results emphasize the complex of dissemination and reassortment events with the movement of migratory birds, and the importance of continual monitoring of AIVs in Japan and Siberia for early alerts to the intrusion of HPAIVs.