青海湖地区禽流感病毒分布情况调查

Survey of avian influenza virus distribution in area around Qinghai Lake

目的了解我国青海湖地区禽流感病毒的分布情况。方法通过系统采集2013年青海湖周边地区野禽和家禽环境标本,采取病毒鸡胚分离的方法,将鸡胚培养物进行流感病毒型别和亚型的鉴定,从而了解禽流感病毒在这一地区的时空分布。同时通过对分离到的禽流感H5N1病毒株进行血凝素基因的测定来判断病毒的致病性。结果共采集2420份野禽和3944份家禽环境标本。野禽环境标本没有分离到病毒,家禽环境标本检测到49份甲型流感病毒阳性标本,病毒分离阳性率为0.77%。共分离到49株病毒,包括27株H9N2病毒,19株高致病性H5N1病毒以及3株H5和H9混合病毒。在家禽环境标本中病毒分离率最高是1月,9月次之。乐都和西宁活禽市场的病毒分离率明显高于其他两个家禽标本采集点。结论本次研究没有在青海湖核心区野禽环境标本中分离到禽流感病毒。在青海湖周边地区的家禽环境标本中分离到49株病毒。属于高致病性禽流感H5N1和低致病性禽流感H9N2。两种病毒在家禽中共同流行的现状增加了禽流感病毒在家禽中的重配,为潜在的流感大流行毒株的出现提供生态学基础。

Objective To understand the distribution of avian influenza virus in the area around Qinghai Lake in China. Methods Wild bird and poultry related samples w ere collected from the environments around Qinghai Lake in2013. Avian influenza viruses w ere isolated w ith embryonated chicken eggs and the subtyping of avian influenza virus w as conducted then. In order to understand the pathogenicity of avian influenza A（ H5N1） viruses,the sequencing of HA genes w ere conducted. Results A total of 2420 w ild bird related samples and 3944 poultry related samples w ere collected. No avian influenza virus strains w ere isolated from w ild bird related samples,but 49 strains of avian influenza A viruses w ere isolated from poultry related samples（ 0. 77%）,including 27 strains of low pathogenic H9N2 virus,19 strains of high pathogenic H5N1 virus and 3 strains of mixed H9N2 and H5N1 viruses. The virus isolation rate in poultry related samples w as highest in January,follow ed by September. The virus isolation rates w ere higher in samples collected from the alive poultry markets in Ledu and Xining. Conclusion No avian influenza viruses w ere detected from the w ild bird related samples collected from core area of Qinghai Lake. All the avian influenza virus strains,including H5N1 strains and H9N2 strains,w ere isolated from the poultry related samples collected from the area around Qinghai Lake. The co-circulating of tw o types of avian influenza viruses w ould facilitate the reassortment of avian influenza viruses,w hich provides the ecological base for the emerging of pandemic influenza virus.