Emergence, Evolution, and Biological Characteristics of H10N4 and H10N8 Avian Influenza Viruses in Migratory Wild Birds Detected in Eastern China in 2020.

H10Nx influenza viruses have caused increasing public concern due to their occasional infection of humans. However, the genesis and biological characteristics of H10 viruses in migratory wild birds are largely unknown. In this study, we conducted active surveillance to monitor circulation of avian influenza viruses in eastern China and isolated five H10N4 and two H10N8 viruses from migratory birds in 2020. Genetic analysis indicated that the hemagglutinin (HA) genes of the seven H10 viruses were clustered into the North American lineage and established as a novel Eurasian branch in wild birds in South Korea, Bangladesh, and China. The neuraminidase (NA) genes of the H10N4 and H10N8 viruses originated from the circulating HxN4 and H5N8 viruses in migratory birds in Eurasia.…