Spatiotemporal Associations and Molecular Evolution of Highly Pathogenic Avian Influenza A H7N9 Virus in China from 2017 to 2021

Viruses

Min Gu¹  Yayao Yan¹  Huiguang Wu¹  Xiaoli Hao¹  Tiansong Zhan¹  Xiaoquan Wang¹  Shunlin Hu¹  Xiaowen Liu¹  Xiyue Wang¹  Jinyuan Gu¹  Dongchang He¹  Jiao Hu¹  Guoqing Wang¹  Xiufan Liu¹  Gairu Li²  Shuo Su²  Chan Ding³ 

[1] Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China;College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China;Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou 225009, China;

关键词: avian influenza virus;    H7N9;    hemagglutinin;    evolution;    highly pathogenic;    epidemiology;   

DOI  :  10.3390/v13122524

来源: DOAJ

【 摘 要 】

Highly pathogenic (HP) H7N9 avian influenza virus (AIV) emerged in China in 2016. HP H7N9 AIV caused at least 33 human infections and has been circulating in poultry farms continuously since wave 5. The genetic divergence, geographic patterns, and hemagglutinin adaptive and parallel molecular evolution of HP H7N9 AIV in China since 2017 are still unclear. Here, 10 new strains of HP H7N9 AIVs from October 2019 to April 2021 were sequenced. We found that HP H7N9 was primarily circulating in Northern China, particularly in the provinces surrounding the Bohai Sea (Liaoning, Hebei, and Shandong) since wave 6. Of note, HP H7N9 AIV phylogenies exhibit a geographical structure compatible with high levels of local transmission after unidirectional rapid geographical expansion towards the north of China in 2017. In addition, we showed that two major subclades were continually expanding with the viral population size undergoing a sharp increase after 2018 with an obvious seasonal tendency. Notably, the hemagglutinin gene showed signs of parallel evolution and positive selection. Our research sheds light on the current epidemiology, evolution, and diversity of HP H7N9 AIV that can help prevent and control the spreading of HP H7N9 AIV.

【 授权许可】

Unknown