一起由H3N2流感病毒引起的局部流感暴发的病原学研究

目的 对一起流感局部暴发的病原体进行分离并鉴定，研究其变异情况，为流感的预防和控制提供依据。方法 用MDCK细胞对病人的咽拭标本进行分离培养，并对分离到的流感病毒HAl基因核苷酸序列进行测定及抗原分析。还检测了患者的血清抗体水平。结果在22份病人的咽拭标本中，分离到3株H3N2亚型流感病毒，患者恢复期血清抗体水平较急性期抗体水平升高4倍。将其中1株的HAl基因测序，与国际代表株进行比较，并与国际代表株进行交叉血抑试验，表明分离到的流感病毒发生抗原漂移。结论这种变异具有流行病学意义，造成甲3亚型流感病毒在湛江地区的局部暴发。

Isolation identification and the variance of influenza A H3N2 virus from an outbreak

Objective The microbial pathogen of a flu outbreak in Zhanjiang city, Guangdong, was isolated, identified and the variance of influenza A H3N2 virus was also studied. Methods The throat swabs from the patients with flu was inoculated into cell cultures. One of the isolates was identified by HAI test, serology, RT-PCR amplification, HA1gene sequence analysis and antigenic analysis. Results Three influenza viruses were isolated from the flu patients. Serological assay indicated that the isolated virus was clearly associated with this strain. 984bp of HA1 segment of virus was amplified by RT-PCR and sequenced, sequence analysis showed that the homology of the amplified HA1 fragments to the previously known reference viruses (A/Panama/2007/99, A/Fujian/411/2002 ) was 97.97 % and 98.88% respectively. According to the genetic analysis of HA, the Zhanjiang isolate is considered to be antigenically different from the reference strains.Conclusion The influenza outbreak caused by H3N2 virus in Zhanjiang city was due to the antigenic and genetic change of the virus.