Molecular epidemiological survey and complete genomic phylogenetic analysis of H6 subtype avian influenza viruses in poultry in China from 2011 to 2016

To investigate the prevalence and evolution of the H6 subtype avian influenza viruses (AIVs) circulating in poultry in China from 2011 to 2016, 11 molecular epidemiological surveys was performed in this study. In total, 893 H6 subtype viral strains were isolated from 67,639 swab samples and 360 environmental samples. From these strains, 35 representative strains were selected and their whole genomic sequences determined. According to a phylogenetic analysis and molecular characterization, all 35 viral strains belonged to the Eurasian avian lineage. All of them were categorized as 'low pathogenic' and a few strains had some bioinformatical mutations. This epidemiological survey shows that the prevalence of H6 subtype AIVs increased from 2012 to 2016 in China, and suggests that infections by H6 subtype AIVs in China has increased in recent years.