内蒙古自治区近两年乙型流感病毒暴发疫情结果分析

Study on results of influenza B outbreak since 2006 in Inner Mongolia

目的:了解近两年来内蒙古自治区由乙型流感病毒引起的暴发疫情的病毒分离情况和病毒抗原性的变异情况及种系分布。方法:采用鸡胚、狗肾传代细胞(MDCK)培养分离流感病毒,经血清学鉴定后提取病毒RNA,经聚合酶链式反应扩增目的基因后进行乙型流感病毒的NS1基因序列测定。结果:2006年1月～2007年4月由爆发疫情共分离到乙型流感病毒55株,血清学鉴定结果除1株为Victoria系毒株以外,其余54株均为Yamagata种系。在时间的分布上2006年全部为Yamagata,而2007年为Victoria系毒株出现。非结构蛋白(NS1)基因片段的核苷酸序列测定结果,两个系列的毒株都有一些小的变异,但Yamagata系的毒株变异更明显些。结论:近两年内蒙古自治区人群中流行的乙型流感病毒已发生抗原漂移,因此加强流感病毒病原学监测,对于防止流感疫情暴发具有重要意义。

Objective：To understand influenza B virus outbreak isolating and circulating and antigenic drift and distributing since 2006 in Inner Mongolia.Methods：Viruses were isolated with chicken embryo and Madin-Darby canine kidney（MDCK） cell.Viral RNA was extracted from the viruses strain after serological identification and transcribed into cDNA by reverse transcrip tase and AMP lified by PCR finally,the PCR product was purified and nucleotide sequence of NS1 gene of the influenza B viruses was analyzed.Results：Fifty-five strains of influenza B viruses were obtained from 2006 to April 2007,including 1of Victoria-lineage and 54 of Yamagata-lineage,On the distribution of time,Victoria-lineage viruses were isolated in 2007 and Yamagata-lineage in 2006.There were several differences in nucleotide acid both Victoria and Yamagata lineages according to the result of sequence analysis of the nonstructural protein（NS1） genes especially.Yamagata lineages viruses were more frequent.Conclusion：Influenza B virus antigenicity is important for influenza surveillance.