广州市2014-2017年登革病毒Ⅰ型流行株E基因演化研究

An evolutionary study on the E gene of DENV-Ⅰ virus in Guangzhou city,2014-2017

目的对2014-2017年广州市登革热流行数据和登革病毒分离株E基因进行分析,寻找广州市登革热的流行规律并进行生物学溯源。方法通过传染病监测网络收集广州市登革热流行数据,对急性期登革热患者血清进行病毒分离培养并对分离到的DENV-Ⅰ型毒株进行E基因测序和系统发生树构建。结果 2014-2017年间,广州市登革热的流行季节均始于5-6月,并在9-10月达到流行的最高峰,从11月开始发病数开始出现断崖式下降,于12月终止;2014年的疫情规模最大,全年总计病例数达到37 340例;广州市登革病毒在演化上有2个主要的来源,分别属于Ⅰ型登革病毒的基因Ⅰ型和基因Ⅴ型。结论 2014-2017年广州市流行的登革病毒Ⅰ型存在2个不同分支,其中南亚来源的基因Ⅴ型分支是2014年大暴发的源头;而东南亚来源的基因Ⅰ型分支一直在本地循环流行,是历年散发流行的主要来源。

Objective To find out the regularity and the biological origin of dengue fever epidemic in Guangzhou city by analyzing the epidemic data and the E gene of DENV-I virus isolates during 2014-2017. Methods The epidemic data of dengue fever in Guangzhou were collected via the infectious disease surveillance network, and the phylogenetic tree of the DENV-I virus E gene were constructed after virus isolation and E gene sequencing. Results During 2014-2017, the epidemic of dengue fever in Guangzhou city started in May and June, reached the peak in September and October, decreased in November and ended in December every year. The largest epidemic occurred in 2014 with 37 340 cases reported. There were 2 branches of DENV-! virus circulating in Guangzhou city, which belong to genotype I and genotype V. Conclusion The circulating DENV-I virus in Guangzhou city during 2014-2017 could be divided into 2 branches： the south Asia-origin genotype V branch caused the outbreak in 2014, and the Southeast Asia-origin genotype I branch had been circulating in Guangzhou city for years, which could be the main source of epidemic in other years.