遗传进化分析在广东省一起HCV“暴发流行”事件中的应用

The evolutionary analysis of hepatitis C virus in an outbreak in Guangdong Province

目的:通过对广东省一起丙型肝炎病毒(HCV)"暴发流行"事件进行遗传进化分析来了解此次事件的起源时间和传播源头。方法:首先对"暴发流行"事件调查中的192例血清样本作为研究组进行基因分型,得到2a亚型和6a亚型,选取相应基因亚型的对照组样本,采用生物信息学相关软件进行遗传进化分析,通过构建的时间尺度树推断此次HCV可能的起源时间及传播源头。结果:此次"暴发流行"事件的192例患者中,66例为2a亚型,119例为6a亚型,未发现其它的基因亚型。对2a亚型数据集以及6a数据集分别进行遗传进化分析提示两者都主要起源于2~5年前,均符合医源性感染的特点。结论:此次广东省HCV"暴发流行"事件中HCV主要基因型为2a和6a,主要起源于2~5年前,符合医源性传播特点,随着时间的延长积累了众多病例导致"暴发"。

Objective To infer its transmission origin and route through studying the feature of molecular epidemiology of an HCV outbreak in Guangzhou. Methods Serum samples 192 cases in an HCV ＂outbreak＂ incident were analyzed for 2a and 6a subtypes. Appropriate genotypes were selected as control group. Informatics software were used in the evolutionary analysis to construct time scale trees and infer the origin time of HCV infection. Results Of 119 patients in the HCV ＂outbreak＂, 66 cases were 2a and llO cases were 6a subtype. No other genotypes were found. The evolutionary analysis indicated the isolates of 2a group and 6a group both originated from 2 ~ 5 years ago. Both of 2a group and 6a group were in llne with the characteristics of iatrogenic infection. Conclusion 2a and 6a were the main sub-genotypes in the Guangdong HCV outbreak investigation and they were originated from 2 to 5 years ago, which were in line with the characteristics of iatrogenic transmission. With the extension of time, a large number of cases accumulated and led to ＂outbreak＂.