关键词: 输入病例, 登革2型病毒, E基因, NS1基因, 序列分析

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.