长沙市活禽市场人H9N2亚型禽流感感染来源的研究

  目的  探讨人H9N2亚型禽流感病毒(avian influenza virus，AIV)的感染来源。  方法  对2014-2015年长沙市活禽市场环境开展AIV核酸监测，收集全球人感染H9N2 AIV病例数据，利用MEGA 6软件对全球人感染H9N2 AIV、活禽市场环境H9N2 AIV和部分禽H9N2 AIV血凝素(hemagglutinin，HA)、神经氨酸酶(neuraminidase，NA)及非结构蛋白(nonstructural protein，NS)基因进行进化分析。  结果  2014-2015年长沙市活禽市场环境中H9 AIV的核酸阳性率最高(占44.76%)，污染较为严重。全球共报告27例人感染H9N2 AIV病例，绝大多数病例经治疗后康复，流行病学调查显示59.26%(16/27)的病例明确有禽类或活禽市场暴露史。HA、NA及NS进化分析显示2013-2016年分离自湖南、广东的人源H9N2 AIV分离株与湖南和广东辖区活禽市场环境中分离到的H9N2 AIV亲缘关系近，核苷酸相似性高达97%~99%。  结论  活禽市场是人H9N2 AIV的感染来源之一。

Study on the source of human infection with H9N2 influenza virus from live poultry markets in Changsha

  Objective  To explore the source of human infection H9N2 avian influenza virus (AIV).  Methods  Environmental AIV nucleic acid monitoring was conducted for live poultry markets in Changsha city from 2014 to 2015, and data of human infection H9N2 subtype AIV cases worldwide were collected. Phylogenetic trees of hemagglutinin(HA), neuraminidase(NA)and non-structural protein(NS)genes from human infection H9N2 subtype AIV, the live poultry markets environmental H9N2 subtype AIV and partial avian H9N2 subtype AIV were constructed using the MEGA 6.06 software, respectively.  Results  In 2014-2015, H9 subtype AIV had the highest nucleic acid positive rate (44.76%) in the live poultry markets environment of Changsha city, and the pollution was serious. A total of 27 cases of human infection with H9N2 subtype AIV had been reported worldwide, and most of these patients recovered after treatments.Epidemiological survey showed that 59.26% (16/27) of cases had a clear history of exposure to poultry or live poultry markets. The phylogenetic trees of HA, NA and NS genes showed that the human infection H9N2 subtype AIV isolates isolated from Hunan and Guangdong were closely related to the H9N2 subtype AIV isolated from the live poultry markets environment in Hunan and Guangdong provinces from 2013 to 2016. The nucleotide similarity was as high as 97%-99%.  Conclusion  Live poultry market is one of the sources of human infection with H9N2 influenza virus.