深圳地区人和鸡群中H9N2亚型流感病毒病原学和血清流行病学调查

目的：了解甲型流感病毒N9N2亚型毒株在深圳地区鸡群和人群中的分布。方法：采用常规的鸡胚双腔法来分离病毒。抗体测定，采用红细胞凝集抑制（HI）试验和中和试验测定法。结果：从深圳地区农贸市场鸡群中分离到27株H9N2亚型流感病毒，但未能从人群中分离到H9N2病毒。约有26％人血清中检测到H9亚型毒株的抗体，（HI滴度≥20），同时还发现抗体阳性率和几何均数随人群年龄增长而增高，同时与职业有关。然而，在鸡群中H9毒株的抗体阳性率仅为7％。结论：禽H9N2毒株不仅能感染人，而且在深圳地区人群和禽类中较为广泛的分布。人H9N2很大可能来源于鸡的H9N2毒株。

Virological and serological surveys for H9N2 subtype of influenza A virus in chickens and men in Shenzhen city

OBJECTIVE: To understand the distribution of influenza A H9N2 virus in chickens and men in Shenzhen area. METHODS: Virus isolation was performed in embryonated hen s eggs with routine method. The antibody to H9N2 virus was detected with micro-hemagglutination inhibition (HI) test, then the results were checked by using the neutralization assay in MDCK cells. RESULTS: Totally 27 strains of influenza A H9N2 virus were isolated from chickens in farm markets in Shenzhen, whereas no H9N2 virus was isolated from men. Approximately 26% of human sera with the HI titers > or =20 to H9N2 virus were detected. However only 7% of chicken sera with the HI titers > or =20 to H9N2 virus were detected. Meanwhile the HI titer and (MGT) of antibody to H9N2 virus in human sera increased with age. It was also found that there was a close relationship between HI antibody titer to H9N2 virus in human sera and occupation. CONCLUSIONS: The distribution of influenza A H9N2 virus in chicken and men in Shenzhen was rather wide. The human H9N2 virus infection probably derived from chicken H9N2 virus.