[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]
J Gen Virol. 2020 Jun 10. doi: 10.1099/jgv.0.001449. Online ahead of print.
Diversity of Avian Influenza A(H5N6) Viruses in Wild Birds in Southern China
Tao Zhang 1 2, Kai Fan 3, Xue Zhang 3, Yujuan Xu 3, Jian Xu 4, Bing Xu 1 2, Ruiyun Li 5
Affiliations: 1 Centre for Healthy Cities, Institute for China Sustainable Urbanization, Tsinghua University, Beijing, PR China. 2 Ministry of Education Key Laboratory for Earth System Modelling, Department of Earth System Science, Tsinghua University, Beijing, PR China. 3 College of Veterinary Medicine, China Agricultural University, Beijing, PR China. 4 School of Geography and Environmental Science, Ministry of Education’s Key Laboratory of Poyang Lake Wetland and Watershed Research, Jiangxi Normal University, Nanchang, Jiangxi, PR China. 5 MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK.
PMID: 32519938 DOI: 10.1099/jgv.0.001449
The predominance of H5N6 in ducks and continuous human cases have heightened its potential threat to public health in China. Therefore, the detection of emerging variants of H5N6 avian influenza viruses has become a priority for pandemic preparedness. Questions remain as to its origin and circulation within the wild bird reservoir and interactions at the wild-domestic interface. Samples were collected from migratory birds in Poyang Lake, Jiangxi Province, PR China during the routine bird ring survey in 2014-16. Phylogenetic and coalescent analyses were conducted to uncover the evolutionary relationship among viruses circulating in wild birds. Here, we report the potential origin and phylogenetic diversity of H5N6 viruses isolated from wild birds in Poyang Lake. Sequence analyses indicated that Jiangxi H5N6 viruses most likely evolved from Eurasian-derived H5Nx and H6N6 viruses through multiple reassortment events. Crucially, the diversity of the HA gene implies that these Jiangxi H5N6 viruses have diverged into two primary clades – clade 18.104.22.168 and clade 22.214.171.124 c. Phylogenetic analysis revealed two independent pathways of reassortment during 2014-16 that might have facilitated the generation of emerging variants within wild bird populations as well as inter-species infections. Our findings contribute to our understanding of the genetic diversification of H5N6 viruses in the wild bird population. These results highlight the necessity of large-scale surveillance of wild birds in the Poyang Lake area to address the threat of regional epizootic epidemics and attendant pandemics.
Keywords: Avian Influenza; H5N6; Reassortant strain; Wild Birds; China.