临沧市静脉注射吸毒人群中HCV基因特征分析

HCV genetic characteristics of intravenous drug users in Lincang prefecture,Yunnan

目的了解云南省临沧市静脉注射吸毒人群(IDUs)中丙型肝炎病毒(HCV)基因型分布和进化特征。方法2018年1-6月,在云南省临沧市收集HCV抗体阳性IDUs的血浆样品102份,进行病毒载量检测,对有病毒载量的样品的E1E2区及NS5B区进行扩增,构建系统进化树确定HCV的亚型,通过Bayesian Markov Chain Monte Carlo(MCMC)方法分析主要亚型的进化特征。结果共71份样品成功分型,共检出3种基因型9种亚型,包括26例(36.6%)3b、16例(22.5%)3a、12例(16.9%)6n、8例(11.3%)1a、3例(4.2%)1b、2例(2.8%)6v、2例(2.8%)6xe、1例(1.4%)6a和1例(1.4%)6xa。HCV亚型在研究对象的人口学特征、病毒载量和是否感染1型艾滋病病毒的分布上无统计学差异。Bayesian进化分析显示1a、1b、3a、3b、6n和6xe亚型的最近共同祖先时间分别为1997.0、1996.8、1989.7、1973.6、2003.1和2007.6。结论临沧市的IDUs中存在多种HCV亚型,不同亚型在不同的时间进入该地的IDUs人群,需要进一步加强对该人群中HCV基因流行特征的监测。

Objective To investigate the distribution and evolutionary characteristics of HCV genotypes among intravenous drug users(IDUs)in Lincang prefecture,Yunnan province.Methods A total of 102 HCV seropositive blood samples were collected from IDUs in Lincang from January to June 2018.All the samples were tested for HCV viral load.E1 E2 and NS5 B genes were amplified from the samples with detected viral load.Phylogenetic and evolutionary analyses were performed.Results Among 71 samples successfully genotyped,3 genotypes and 9 subtypes were identified,including subtypes 3 b(36.6%,26/71),3 a(22.5%,16/71),6 n(16.9%,12/71),1 a(11.3%,8/71),1 b(4.2%,3/71),6 v(2.8%,2/71),6 xe(2.8%,2/71),6 a(1.4%,1/71)and 6 xa(1.4%,1/71).The distributions of HCV subtypes showed no statistical significance by the demographic characteristics,HCV viral load and the status of HIV-1 infection.Bayesian evolutionary analysis indicated that times of most recent common ancestor of subtypes 1 a,1 b,3 a,3 b,6 n and 6 xe subtypes were 1997.0,1996.8,1989.7,1973.6,2003.1 and 2007.6,respectively.Conclusion Various HCV subtypes are prevalent among IDUs in Lincang.It is necessary to further monitor the prevalence characteristics of HCV genetics in this sub-population.