中文摘要：

目的分析引起吉林省2009--2010年手足口病（hand foot and mouth disease，HFMD）流行的肠道病毒71型的基因进化特征。方法选择31株2009-2010年分离于吉林省8个地市（州）HFMD病例的EV71代表株，对VP1编码区基因进行逆转录．聚合酶链反应扩增、扩增产物的序列测定，使用Bioedit软件和MEGA4．0软件对VP1基因进行同源性、基因亲缘关系分析。结果吉林省2009-2010年的31株EV71分离株均属于C4a基因亚型，3l株EV7t株在VP1区的核苷酸的同源性在94．5％～100％之间，分属于5个分支，其中25株病毒（分离于8个地市）形成一个大的分支，属于绝对优势传播链，其余6株形成4个小分支。结论2009-2010年在吉林省内有多个EV71C4a基因型的传播链同时存在，其中分支1为绝对优势传播链，在8个地市持续传播，引起HFMD的暴发流行。

英文摘要：

Objective To analyze the genetic characterization of enterovirus type71 （ EVTI ） associated with hand foot and mouth disease （HFMD） epidemics in Jilin province, during 2009-2010. Methods Randomly selected 31 representative EV71 strains from the cases of 8 prefectures to amplify and sequences of VP1 genes of EV71 strains, and analyzed with Bioedit and Mega4.0 program. Results All representative 31 EVT1 strains belong to C4a subgenotype, the homology of nucleotide in VP1 region among the 31 EV71 strains were 94. 5% -100. 0% , and were clustered into 5 transmission chains respectively. 25 strains out of 31 strains were associated with a predominant transmission chain, and circulating in 8 prefectures, while other 6 strains clustered into 4 lineages. Conclusion Multiple transmission chains of EVT71 C4a subgenotype were co-circulating in Jilin province during 2009-2010, and a predominant transmission chain was circulating in 8 prefectures, associated with HFMD outbreaks of Jilin province.