深圳市一起输入性基孔肯雅热疫情的分子流行病学研究

Molecular epidemiological analysis of an imported Chikungunya fever in Shenzhen

目的对2012年深圳市一起输入性疑似基孔肯雅热病例病原学特征进行分析。方法对疑似病例血清标本采用ELISA和荧光PCR方法分别检测基孔肯尼雅病毒Ig M、Ig G抗体和核酸,并用C6/36细胞分离病毒。采用荧光定量逆转录PCR方法扩增病毒结构蛋白基因后进行序列测定,并与不同国家和地区的毒株进行同源性比较和进化树分析。结果深圳市2012年7月报告的一起基孔肯雅热疫情为输入性病例。从病例血清标本中检测到病毒核酸,并成功分离到基孔肯尼雅病毒,将其命名为CHIKV-SZ1239。SZ1239株与非洲原型株S27-African、我国广东省2010年暴发疫情株GD05/2010、印度尼西亚2011年流行株CHIK/SBY83/11在E1基因上核苷酸同源性分别为94.0%、93.1%、98.8%。进化树显示SZ1239株与2011年新喀里多尼亚分离株NC/2011/568亲缘关系最近,其次为印度尼西亚流行株,属于Asian基因型。结论从病原学和分子生物学特征上均证实该例基孔肯雅热输入病例是由基孔肯尼雅病毒Asian基因型引起,病毒遗传特征与印度尼西亚地区流行CHIKV一致。

Objective To study the etiology characteristics of an imported Chikungunya fever case reported in Shenzhen in2012. Methods The serum sample collected from the suspect Chikungunya fever case was detected for Ig M,Ig G and Chikungunya virus nucleic acid by ELISA and real-time RT-PCR. C6 /36 cells were adopted for virus isolation. Protein gene was amplified by RT-PCR and sequenced to construct homology comparison and phylogenetic tree analysis. Results The case was laboratory confirmed imported Chikungunya disease cases in Shenzhen on July 2012. RNA of Chikungunya virus was detected in the serum sample. Chikungunya virus named CHIKV-SZ1239 was successfully isolated from the serum sample. The homology of nucleotide sequence of E1 gene of SZ1239 with African prototype S27-African strain,GD05 /2010 strain,CHIK / SBY83 /11 strain were 94. 0%,93. 1% and 98. 8%,respectively. The phylogenetic tree indicated that SZ1239 was most close to NC /2011 /568 strain,followed by strains in Indonesia belonging to Asian genotype. Conclusion The virological and molecular features showed that the imported case of Chikungunya fever was caused by CHIKV Asian genotype,and the genetic characteristics of the SZ1239 virus strain are consistent with CHIKV popular in Indonesia.