Novel H5N6 viruses were first documented in Laos in 2013 and subsequently reported in Vietnam and China1, but these viruses did not initially attract a great deal of attention. Instead, there was a greater focus on known H5N6 subtype AIVs until a fatal human infection with a novel H5N6 virus was confirmed in Sichuan Province, China2. As of May 2017, 17 human infections with these novel H5N6 highly pathogenic avian influenza viruses (HPAIVs), including 12 deaths, have been identified3.


H5N6 was identified as one of the dominant AIV subtypes among poultry in southern China4. However, as of June 2017, few cases involving wild birds infected with H5N6 AIVs have been reported in China, and these cases have been reported only in central (Hubei) and eastern China (Jilin, Guangdong)2,4,5. We first reported novel H5N6 HPAIVs infections in eight species of migratory birds in western China.


In November 2015, oropharyngeal and cloacal swabs from 80 wild waterfowl were collected during active surveillance at Changshantou reservoir, Ningxia, western China (Fig. 1a). Viruses were isolated in 10-day-old specific pathogen-free chicken embryos, and 17 samples were positive for H5N6 avian influenza virus according to RT-PCR detection; thus, the separation rate was 21.25% (17/80). All sequences determined in this study were confirmed by Sanger sequencing and have been submitted to GenBank under accession numbers MF399537–MF399672. We performed further experiments, including a receptor-binding specificity assay, a mouse pathogenicity test, and a guinea pig transmission test, to evaluate the pathogenicity and transmissibility of the isolated viruses