title: Genetic Characterization of Continually Evolving Highly Pathogenic H5N6 Influenza Viruses in China, 2012-2016.
abstract: H5N6 is a highly pathogenic avian influenza (HPAI) and a zoonotic disease that causes recurring endemics in East Asia. At least 155 H5N6 outbreaks, including 15 human infections, have been reported in China. These repeated outbreaks have increased concern that the H5N6 virus may cross over to humans and cause a pandemic. In February, 2016, peafowls in a breeding farm exhibited a highly contagious disease. Post-mortem examinations, including RT-PCR, and virus isolation, confirmed that the highly pathogenic H5N6 influenza virus was the causative agent, and the strain was named A/Pavo Cristatus/Jiangxi/JA1/2016. In animal experiments, it exhibited high pathogenicity in chickens and an estimated median lethal dose in mice of ~104.3TCID50. A phylogenetic analysis showed that JA1/2016 was clustered in H5 clade 2.3.4.4. FG594-like H5N6 virus from Guangdong Province was the probable predecessor of JA1/2016, and the estimated divergence time was June 2014. Furthermore, we found that H5N6 influenza viruses can be classified into the two following groups: Group 1 and Group 2. Group 2 influenza viruses have not been detected since the end of 2014, whereas Group 1 influenza viruses have continually evolved and reassorted with the "gene pool" circulating in south China, resulting in the rise of novel subtypes of this influenza virus. An increase in the number of its identified hosts, the expanding range of its distribution, and the continual evolution of H5N6 AIVs enhance the risk that an H5N6 virus may spread to other continents and cause a pandemic.
authors.affiliation: National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of SciencesBeijing, China; College of Life Science, University of Chinese Academy of SciencesBeijing, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.affiliation: National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of SciencesBeijing, China; College of Life Science, University of Chinese Academy of SciencesBeijing, China.
authors.forename: Na
authors.initials: N
authors.lastname: Zhao
authors.affiliation: National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Animal Science, Hebei Normal University of Science and Technology Qinghuangdao, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of SciencesBeijing, China; College of Life Science, University of Chinese Academy of SciencesBeijing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of SciencesBeijing, China; College of Life Science, University of Chinese Academy of SciencesBeijing, China.
authors.forename: Jiajun
authors.initials: J
authors.lastname: Ma
authors.affiliation: National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences Beijing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhao
authors.affiliation: National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences Beijing, China.
authors.forename: Guohui
authors.initials: G
authors.lastname: Yuan
authors.affiliation: National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences Beijing, China.
authors.forename: Chengmin
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Microbiology, Beijing General Station of Animal Husbandry Beijing, China.
authors.forename: Yutian
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Microbiology, Beijing General Station of Animal Husbandry Beijing, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Liu
authors.affiliation: National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences Beijing, China.
authors.forename: Hongxuan
authors.initials: H
authors.lastname: He
keywords: H5N6; Pavo cristatus; genetic reassortment; highly pathogenic avian influenza; molecular characterization; phylogenetic analysis