中文摘要：

目的研究天津市秋冬季婴幼儿腹泻患儿中诺如病毒感染的流行情况及其基因型别。方法 2008年10-12月收集天津市儿童医院住院部310例疑似病毒性腹泻的婴幼儿粪便标本,应用逆转录聚合酶链反应（RT-PCR）法检测粪便中诺如病毒核酸,并将部分阳性株的PCR产物进行测序,采用序列分析软件分析测序结果 ,推断其毒株型别。结果 310份腹泻标本中,诺如病毒RT-PCR阳性37份（GII型37份,GI型0例）,检出率为11.94%;23份PCR产物送往测序,经Genebank Blast及系统进化树分析,所有诺如病毒均为诺如病毒基因组Ⅱ型,其中GII-4/2006b占95.65%（22/23）,GII-3占4.35%（1/23）;感染诺如病毒的患儿多为1岁以下,且11月份检出率最高。结论诺如病毒是天津市秋冬季婴幼儿病毒性腹泻的重要病原体,2008年诺如病毒以GII-4/2006b型毒株流行为主。

英文摘要：

Objective To explore the prevalence and the genetic diversity of norovirus among diarrheic children in Tianjin.Methods A total of 310 fecal specimens were collected during the period of October through December,2008 from infants and children with viral diarrhea hospitalized at the Tianjin Children’s Hospital.Norovirus was detected with reverse transcription-polymerase chain reaction（RT-PCR） of the capsid gene and confirmed by sequencing,then followed by phylogenetic analysis.Results Among 310 specimens,37（11.94%） were positive for norovirus by RT-PCR.By comparative analysis with Genebank Blast and phylogenetic analysis of 23 norovirus sequences,22 norovirus cases（95.65%） were GII-4/2006b and 1 norovirus case（4.35%） was GII-3.Children aged less than 1 year were the most susceptible population to nornvirus infection which were usually found in November.Conclusion Norovirus is the major causal agents of viral diarrhea among hospitalized children with gastroenteritis in Tianjin and norovirus GII-4/2006b is a predominant genotype in 2008.