陕西省赴柬埔寨务工人员归国后暴发登革热疫情调查分析

Analysis of dengue fever outbreak among workers returning from Cambodia in Shaanxi province,2007

目的确定2007年陕西省赴柬埔寨务工人员归国后发热疫情病因。方法采集陕西省70例赴柬埔寨务工归国人员的血清标本,使用血清学方法进行登革病毒IgM和IgG检测;使用逆转录-巢式-聚合酶链反应(RT-nPCR)扩增发热患者血清中登革病毒RNA;同时,对发热患者血清进行登革病毒的分离培养。结果使用CORTEZ公司快检试剂共检出7份IgM阳性血清,其中发热患者5例;使用IBL公司IgM试剂盒共检出6份IgM阳性血清,其中发热病例4例。使用IBL公司登革热IgG ELISA试剂盒共检出13份IgG阳性血清,包括2例发热患者。使用RT-nPCR方法从首例发热患者的血清中扩增出登革病毒目的片段,经序列比对结果证实是DEN-1型病毒核酸片段。用C6/36细胞和BHK细胞未分离出登革病毒。结论根据患者的临床症状、流行病学史以及实验室诊断结果,共确诊了4例输入性登革热病例,其中首发病例为DEN-1型病毒感染。血清学检测结果表明,在归国人员中还存在隐性感染者。

Objective To identify the cause of an outbreak of fever among the workers returning from Cambodia in Shaanxi province in 2007. Methods Blood samples were taken from 70 workers returning from Cambodia to detect IgM and IgG to dengue virus, dengue virus RNA in serum of the febrile cases was amplified by RT-nested-PCR, and dengue virus isolation from serum of the febrile cases was conducted. Results Seven samples （ including 5 samples from the febrile cases） were positive for IgM and none of the serum samples were positive for IgG by reagent from CORTEZ, and 6 samples （including 4 samples from the febrile cases ） were positive for IgM by IgM kit from IBL and 13 samples （including 2 samples of the febrile cases） were positive for IgG by IgG kit from IBL. A specific DNA fragment of DEN-1 virus was amplified from serum of the index case, which was confirmed by sequence analysis. No virus was isolated by C6/36 and BHK cells. Conclusion Four imported dengue fever cases were confirmed according to the experiment results, symptoms and epidemiology history, and the index case was infected with DEN-1 virus. The serological results indicated that there was asymptomatic infection among the returned workers.