Li Meng, Zhao Na, Luo Jing, Li Yuan, Chen Lin, Ma Jiajun, Zhao Lin, Yuan Guohui, Wang Chengmin, Wang Yutian, Liu Yanhua, He Hongxuan
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.
National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences Beijing, China.
Front Microbiol. 2017 Feb 28;8:260. doi: 10.3389/fmicb.2017.00260. eCollection 2017.
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//Jiangxi/JA1/2016. In animal experiments, it exhibited high pathogenicity in chickens and an estimated median lethal dose in mice of ~10 TCID. 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.
H5N6是一种高致病性禽流感（HPAI），也是一种人畜共患病，在东亚地区引发了反复的地方流行。中国已报告至少155起H5N6疫情，其中包括15例人类感染病例。这些反复出现的疫情加剧了人们对H5N6病毒可能传播给人类并引发大流行的担忧。2016年2月，一个养殖场的孔雀出现了一种高度传染性疾病。包括逆转录聚合酶链反应（RT-PCR）和病毒分离在内的尸检证实，高致病性H5N6流感病毒是病原体，该毒株被命名为A//江西/JA1/2016。在动物实验中，它对鸡表现出高致病性，在小鼠中的估计半数致死剂量约为10个组织培养感染剂量（TCID）。系统发育分析表明，JA1/2016聚集在H5进化分支2.3.4.4中。来自广东省的FG594样H5N6病毒可能是JA1/2016的前身，估计分歧时间为2014年6月。此外，我们发现H5N6流感病毒可分为以下两组：第1组和第2组。自2014年底以来未检测到第2组流感病毒，而第1组流感病毒不断进化，并与中国南方传播的“基因库”发生重配，导致这种流感病毒新亚型的出现。其已识别宿主数量的增加、分布范围的扩大以及H5N6禽流感病毒的不断进化，增加了H5N6病毒传播到其他大陆并引发大流行的风险。
