广东省肇庆市2014-2015年登革病毒分子分型及初步溯源研究

目的 了解广东省肇庆市2014-2015年登革病毒（DENV）的基因型别和可能的输入来源。方法 收集登革热临床诊断病例急性期血清，对实时荧光反转录-聚合酶链反应（RT-PCR）检测阳性标本进行病毒培养，分离株进行E基因扩增与序列测定，用Mega 5.1软件进行分子分型和系统进化树构建。结果 409份样品中147份实时荧光RT-PCR检测阳性（35.94%），其中2014年阳性144份（39.99%），以DENV 1（139/361）为主；2015年阳性3份（6.25%），以DENV 3（2/48）为主。共获得22株DENV分离株，其中20株为2014年DENV 1型的genotype Ⅰ和Ⅲ，与2013-2014年广州、佛山市分离株核苷酸同源性分别为99.40%~100.00%和99.20%~100.00%，与新加坡、泰国、马来西亚和印度尼西亚分离株亲缘关系次之；2株为2015年DENV 3的genotype Ⅲ，与近年新加坡和印度尼西亚分离株的核苷酸同源性为98.20%~99.70%。结论 广东省肇庆市2014年暴发流行的DENV 1为genotype Ⅰ和Ⅲ，可能由广州市和佛山市输入，2015年散发的DENV 3为genotype Ⅲ，由佛山市输入，疫情毒株可能源于新加坡、印度尼西亚等东南亚流行株。

Genotyping and molecular tracing of dengue virus in Zhaoqing,Guangdong, 2014-2015

Objective To understand the origins and genotypes of dengue virus circulating in Zhaoqing in Guangdong province from 2014 to 2015. Methods Blood samples were collected from clinical dengue fever cases in Zhaoqing from 2014 to 2015 and detected by using real-time RT-PCR. The positive samples in PCR were used for virus isolation. The E genes from isolated strains were amplified and sequenced, the phylogenetic tree was constructed and homology analysis were performed with Mega 5.1 software. Results In 409 samples detected in real-time RT-PCR, 147 were positive, in which 139 of 144 were positive for DENV 1 in 2014 and 2 of 3 were positive for DENV 3 in 2015, respectively. A total of 22 strains of dengue virus were isolated and identified. Phylogenetic analysis showed that the 20 strains of DENV 1 isolated in 2014 belonged to genotype Ⅰ and Ⅲ, sharing 99.40%-100.00% and 99.20%-100.00% homology with the strains isolated in Guangzhou and Foshan during 2013-2014, respectively, but low homology with the strains isolated in Singapore, Thailand, Malaysia and Indonesia. The 2 DENV 3 strains isolated in 2015 were identified as genotype Ⅲ, sharing 98.20%-99.70% homology with the strains isolated in Singapore and Indonesia in recent years. Conclusion DENV 1 belonging to genotype Ⅰ and Ⅲ was the pathogen causing dengue fever outbreak in Zhaoqing in 2014, which might spread from Guangzhou and Foshan, while the DENV 3 detected in sporadic infections belonged to genotype Ⅲ, which might spread from Foshan in 2015. All the strains might originated from Southeast Asian countries, such as Singapore and Indonesia.