Abstract: Objective To determine the etiology of an imported dengue fever case reported in 2004 in Zhejiang province and to provide diagnostic proof for the disease prevention and control,the molecular characteristics of the isolated dengue virus was studied.Methods The serum sample collected from the suspect dengue fever case was detected for IgM,IgG by ELISA,IFA and dengue virus nucleic acid by real-time RT-PCR.The samples were further inoculated in C6/36 and BHK-21 cells for virus isolation.E and NS1 genes of the isolated strain were amplified by RT-PCR and sequenced.Phylogenetic and homology trees of E and NS1 genes of the Zhejiang dengue virus with the strains isolated from other areas were constructed.Results(IgM,IgG) and RNA of type 2 dengue virus were detected in the serum sample and type 2 dengue virus named Zhejiang/01/04 was isolated from the serum sample.The homology of amino acid of E gene of Zhejiang/01/04 with standard type 2 dengue virus Jamaica strain,Fujian/10/99 strain and Saudi/92 strain were(97.1%),(99.2%) and(99.6%) respectively,but the homology with dengue virus type 1,3,4 in the same fragment were(68.7%),(66.9%) and(63.6%).The phylogenetic tree indicated that Zhejiang/01/04 had the greatest similarity with the Saudi/92 strain and they lied in the same branch of the phylogenetic tree.Conclusion The virological,serological and molecular features all showed that the imported case of dengue fever was caused by type 2 dengue virus which was most likely from Saudi Arabia.

摘要： 目的 为了对2004年浙江省报告的输入性疑似登革热病例查明病因,从分子水平分析流行毒株的生物学特征,追踪传染源,为疾病的预防控制提供实验室依据。方法 对疑似患者血清标本采用ELISA、IFA和荧光RT-PCR方法分别检测登革病毒IgMI、gG抗体和病毒核酸,并用C6/36和BHK-21细胞分离登革病毒。采用RT-PCR方法扩增病毒E基因和NS1基因后分别进行序列测定,并与不同国家和地区的登革热毒株进行同源性和进化树分析。结果 从患者血清中检测到登革病毒IgM、IgG抗体和登革2型病毒核酸,并分离到登革2型病毒;浙江省登革2型病毒分离株(ZJ/01/04)与登革2型国际标准株Jamaica、国内Fujian/10/99株和Saudi/92株在E基因上氨基酸的同源性分别为97.1%、99.2%和99.6%,而与登革1、3、4型毒株相同区域氨基酸同源性分别为68.7%、66.9%和63.6%。基因进化树显示ZJ/01/04分离株与Saudi/92株亲缘关系最近,在进化树的同一分支上。结论 从病原学、血清学和分子生物学特征上均证实该输入病例是由登革2型病毒引起,该毒株最有可能来源于沙特阿拉伯。

关键词: 输入病例, 登革2型病毒, E基因, NS1基因, 序列分析