上海市浦东新区注射吸毒者HCV的进化分析与正选择位点研究  

Evolutionary characteristics and positive selection site of hepatitis C virus isolated in intravenous drug users in Pudong new district, Shanghai

作　　者：王郁[1] 吴红岩[2,3] 赵希畅[2,3] 朱渭萍[2,3] 万千[2,3] 陆一涵[1,3] 姜庆五[1] 

机构地区：[1]复旦大学公共卫生学院,公共卫生安全教育部重点实验室,上海200032 [2]上海市浦东新区疾病预防控制中心,200120 [3]复旦大学浦东预防医学研究院,上海200120

出　　处：《中华流行病学杂志》2017年第3期378-383,共6页Chinese Journal of Epidemiology

基　　金：上海市卫生局局级课题（20134241）;上海市第四轮公共卫生三年行动计划重点学科建设项目（15GWZK0101）

摘　　要：目的了解上海市浦东新区注射吸毒者分离的HCV的基因分型，分析其病毒种群的增长演化过程与选择压力。方法采集美沙酮门诊注射吸毒者血清200份，扩增HCVNS5B377-nt核苷酸片段。结合同期当地的志愿献血者、MSM、法定报告丙型病毒性肝炎（丙肝）病例的分离序列，使用BEAST软件包分析主要基因型的进化速率和种群演变过程。采用Datamonkey在线软件包对注射吸毒者分离序列分析选择压力，并与直接抗病毒药物（Direct-actingantiviral，DAA）结合位点进行比对。结果美沙酮门诊注射吸毒者HCVRNA阳性检出率19．5％（39／200），其中基因分型分为3a亚型（14份）、3b亚型（13份）、1b亚型（7份）、6a亚型（4份）和6n亚型（1份）。注射吸毒者分离序列与其他人群序列同源性均较高。进化分析表明，HCV1b亚型的理论感染人数于20世纪90年代开始增加且增速较快，3a与3b亚型则从90年代中期呈逐渐上升趋势。选择压力分析显示，注射吸毒者NS5B377-nt片段确认有2个正选择位点，在7个DAA结合位点的突变率为2．2％。结论HCV3a和3b亚型是上海浦东注射吸毒者丙肝感染的主导基因型。而1b亚型在各人群中普遍分布，进化速率较快，其导致的感染数将持续上升。注射吸毒者HCVNS5B基因片段的DAA结合位点突变率低，预计药物结合效果较好。Objective To understand the genotypes of hepatitis C virus （HCV） circulating in intravenous drug users （IDUs） in Pudong new district, Shanghai, and explore the population growth and selection pressure of the HCV strains isolated. Methods A total of 200 serum specimens sampled from IDUs in local methadone maintenance treatment clinic in Pudong were used for amplification of a HCV NS5B 377-nt partial sequence. Mean evolutionary rate and effective number of infections were estimated based on the 377-nt partial sequences of the HCV strains isolated from IDUs and isolated contemporarily from local voluntary blood donors, men who have sex with men and reported hepatitis C cases by using BEAST software. Selection pressure sites were identified with online Datamonkey software for subsequent comparison with direct-acting antiviral （DAA） drug binding sites. Results A total of 39 （19.5%） serum specimens were positive for HCV RNA. The genotypes were determined based on the HCV NS5B 377-nt partial sequences as follows： subtype 3a （n= 14）, 3b （n= 13）, lb （n= 7）, 6a （n=4） and 6n （n= 1）. The partial sequences of the HCV strains isolated in IDUs shared high homology with the sequences of the HCV strains isolated in other populations. The Bayesian Skyline Plot indicated that the estimated infections with HCV subtype lb increased exponentially during the 1990s, whereas that of subtypes 3a and 3b increased slowly since the mid-1990s. In the NS5B 377-nt partial sequences of the HCV strains isolated in IDUs, there were two positive selection sites and seventy-eight negative selection sites recognized. The mutation rate was as low as 2.2% in the 377-nt partial sequences corresponding to the known seven DAA drug binding sites. Conclusions HCV subtype 3a and 3b were the predominant genotypes in the IDUs in Pudong. Subtype lb was prevalent in different populations and evolved very rapidly, and more infections might be caused, suggesting further attention to its prevention, control and treatment. Altho

关 键 词：丙型肝炎病毒 基因型 进化分析 正选择位点 

分 类 号：R181[医药卫生—流行病学] R512.63[医药卫生—公共卫生与预防医学]