贵州吸毒人群丙型肝炎病毒感染者的基因分型研究

Hepatitis C virus genotyping analysis among drug users in Guizhou,China

目的了解贵州吸毒人群丙型肝炎病毒(HCV)感染者的基因亚型分布,为该省吸毒人群HCV临床治疗和估计HCV造成疾病负担提供参考信息。方法抽取贵州省部分美沙酮门诊和强制戒毒所吸毒人员血浆样本,经过初筛和复检,筛选HCV抗体阳性样本;提取HCV核酸后,用巢式RT-PCR扩增5′-UTR区段进行HCV核酸的定性检测(nucleic acids technology,NAT),以筛选HCV核酸阳性样本;再用巢式RT-PCR扩增NS5B区段,对凝胶电泳条带阳性扩增产物进行测序,将清理后的序列与HCVDatabase提供的NS5B区段参考序列比对,使用MEGA 4.0做系统进化树,进行基因分型。结果 309份抗体阳性样本中核酸阳性258份(83.5%),成功分型246份,10份测序区扩增失败,2份测序失败。246份中1a6份,1b25份,3a62份,3b79份,6a69份,6n5份。吸毒人群HCV感染者的基因亚型仅在不同性别和吸毒方式间的分布上差异有统计学意义。NAT(-)与NAT(+)样本HCV抗体酶联免疫吸附法检测S/CO比值差异无统计学意义。结论贵州吸毒人群HCV感染者的基因型主要为3型和6型、少数为1型,未发现2型、4型和5型;性别和吸毒方式影响吸毒人群HCV感染者基因亚型的分布。

Objective To study the distribution of hepatitis C virus （HCV） genotypes among drug users in Guizhou, China and provide guidance for HCV clinical treatment and estimate the burden of hepatitis C infec- tion in this special population. Methods Serum samples were collected from drug users in Methadone Clinics and Detention Centers in Guizhou, China. ELISA-sereened anti HCV positive samples were further subject to HCV RNA extraction using Nucleic Acids Technology （NAT） that targets the 5＇ untranslated region （5＇- UTR）. Next, the NSSB region was amplified for sequencing analysis, and software ChromasPro, BioEdit and MEGA 4.0 were used to construct the phylogenetic tree. Results There was no significant difference in the S/CO ratios between ELISA and NAT detection. More male drug users were found than females; younger age and divorce were additional risk factors in drug addiction. 258 samples showed HCV RNA positive out of a total of 309 anti-HCV positive ones; successful sequencing was done with 246 samples for further genotyping analysis. Genotypes la, lb, 3a, 3b, 6a and 6n were identified in 6, 25, 62, 79, 69 and 5 samples, respectively. Conclusions Genotype 3 and 6 are the main HCV strains among drug users in Guizhou, China.