Emerging Microbes and Infections (Dec 2023)

Prevalence, evolution, replication and transmission of H3N8 avian influenza viruses isolated from migratory birds in eastern China from 2017 to 2021

  • Yanwen Wang,
  • Mengjing Wang,
  • Hong Zhang,
  • Conghui Zhao,
  • Yaping Zhang,
  • Jinyan Shen,
  • Xiaohong Sun,
  • Hongke Xu,
  • Yujiao Xie,
  • Xinxin Gao,
  • Pengfei Cui,
  • Dong Chu,
  • Yubao Li,
  • Wenqiang Liu,
  • Peng Peng,
  • Guohua Deng,
  • Jing Guo,
  • Xuyong Li

DOI
https://doi.org/10.1080/22221751.2023.2184178
Journal volume & issue
Vol. 12, no. 1

Abstract

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ABSTRACTThe continued evolution and emergence of novel influenza viruses in wild and domestic animals poses an increasing public health risk. Two human cases of H3N8 avian influenza virus infection in China in 2022 have caused public concern regarding the risk of transmission between birds and humans. However, the prevalence of H3N8 avian influenza viruses in their natural reservoirs and their biological characteristics are largely unknown. To elucidate the potential threat of H3N8 viruses, we analyzed five years of surveillance data obtained from an important wetland region in eastern China and evaluated the evolutionary and biological characteristics of 21 H3N8 viruses isolated from 15,899 migratory bird samples between 2017 and 2021. Genetic and phylogenetic analyses showed that the H3N8 viruses circulating in migratory birds and ducks have evolved into different branches and have undergone complicated reassortment with viruses in waterfowl. The 21 viruses belonged to 12 genotypes, and some strains induced body weight loss and pneumonia in mice. All the tested H3N8 viruses preferentially bind to avian-type receptors, although they have acquired the ability to bind human-type receptors. Infection studies in ducks, chickens and pigeons demonstrated that the currently circulating H3N8 viruses in migratory birds have a high possibility of infecting domestic waterfowl and a low possibility of infecting chickens and pigeons. Our findings imply that circulating H3N8 viruses in migratory birds continue to evolve and pose a high infection risk in domestic ducks. These results further emphasize the importance of avian influenza surveillance at the wild bird and poultry interface.

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