广东省一起HCV“暴发流行”事件遗传进化分析

Significance and Distribution of HCV Genotypes in an Outbreak in Guangdong Province in 2012

【目的】分析地区聚集性感染事件中HCV感染者的HCV基因型分布及进化特点,推断其传播途径。【方法】研究组192个样本,126人来自响水街的一个小区域(以ZJBL命名),均有在响水街某诊所接受医疗护理的病史,66个样本取自紫金县周边地区(以ZJ命名)。采用多片段巢式PCR法,检测研究组HCV感染者的HCV基因型;应用病例对照研究方法比较其他地区同基因型HCV感染者的分布特点,推断HCV的可能感染途径。【结果】192例患者中,66例为基因亚型2a,119例为基因亚型6a,未发现其他的基因亚型。2a型感染者HCV-RNA病毒定量(lg ncopy/m L)低于HCV-6a型感染者,差异具有统计学意义(5.45±1.15 vs 5.98±1.37,P<0.05)。系统进化分析显示,与对照组比较,研究组序列形成密切的集群,表明它们可能来自共同的感染源。【结论】紫金县HCV聚集性感染事件中HCV主要基因型为2a和6a,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 study the distribution feature of HCV genotypes in an outbreak in Guangdong Province in 2012 and identify the probable transmission routes of HCV. [Methods] There were 192 samples in the study group, 126 were from a small area called Xiang Shui Street （named ZJBL）, all of whom had received medical care from a same clinic at Xiang Shui Street. 66 samples were taken from the surrounding area of Zijin County （named ZJ）. HCV genotypes were detected by amplification of different parts of the genomes by the nest-specific primers PCR. The distribution features of HCV genotypes in this outbreak were compared to the controls by case control study. [Results] Of the 192 patients, we characterized HCV subtype 2a and 6a sequences from 66 and 119 patients, respectively. 66 cases of HCV-2a and 119 cases of HCV-6a had the same residential location, age and gender differences were not statistically significant （P〉0.05）. For HCV- RNA virus quantitative determination （lg ncopy/mL）, HCV-2a cases had a low level of HCV- RNA virus quantitative than HCV-6a cases, the difference was statistically significant （5.45 ± 1.15 vs 5.98 ± 1.37, P 〈 0.05）. Then we co-analyzed them with controls with the same genotypes but from other areas. The close grouping of the patients＇ sequences contrasted sharply with the diversity of controls. [ Conclusion ] HCV sequences from the study patients grouped into 2a and 6a clusters. The revolutionary pattern of the HCV met the characteristics of iatrogenic transmission routes, HCV strains were highly selected and preferentially spread.