2007-2009年湖南省流行性感冒病原学监测结果分析

Analysis on Pathogenic Monitoring Results of Influenza in Hunan Province from 2007 to 2009

目的了解湖南省2007-2009年流感监测地区的流感流行状况及毒株的型别分布,并分析其流行趋势,为流感防控提供科学依据。方法采集流感样病例(ILI)的咽拭子标本,采用传代狗肾细胞(MDCK)直接进行病毒分离,或应用RT-PCR方法先对标本进行流感病毒核酸检测,核酸检测阳性的标本进行病毒分离,分离到的毒株采用血凝抑制实验(HI)进行流感病毒型别鉴定。结果全省哨点医院共采集24049份ILI咽拭子标本,分离到毒株1898株,分离阳性率7.89%,鉴定结果为:季节性A(H1N1)亚型517株,季节性A(H3N2)亚型821株,B型268株,新甲型H1N1292株。结论 2007-2008年湖南省流感活动呈典型的双峰分布,2009年由于新甲型H1N1的流行,在2009年9-12月间形成第三个高峰。2007年1月-2008年6月以季节性A(H3N2)亚型为优势毒株,2008年7月-2009年9月转变为以季节性A(H1N1)亚型为优势毒株,至2009年9-12月间转变为以新甲型H1N1为优势毒株。

Objective To understand the influenza epidemic situation and the distribution of the virus type in Hunan Province from 2007 to 2009,to analyze the epidemic trend,and to provide the scientific evidence for the disease control.Methods Throat swabs were collected from influenza-like illness（ILI）cases.The strains were isolated by Madin-Darby Canine Kidney（MDCK）cell directly or firstly tested by RT-PCR and the positive samples were then isolated by MDCK cell.The types of influenza virus were confirmed by hemagglutination inhibition（HI）test.Results Totally 24,049 ILI throat swab samples were collected from sentinel hospitals in Hunan Province.1,898 strains were identified as positive,and the positive rate of isolation was 7.89%.The identification results showed that 517 strains were seasonal A（H1N1）subtype,821 strains seasonal A（H3N2）subtype,268 strains influenza B,and 292 strains new influenza A（H1N1）.Conclusions The bimodal distribution was presented from 2007 to 2008 and the third peak was formed from September to December,2009 in Hunan Province for the epidemic of influenza A/H1N1.The prevailing strain was seasonal A（H3N2）subtype from January,2007 to June,2008.But from July,2008 to September,2009,the prevailing strain was turned to seasonal A（H1N1）subtype and then turned to new influenza A（H1N1）subtype from September to December,2009.