中国不同基因型/亚型丙型肝炎病毒混合感染率的研究

The prevalence of mixed-genotype of HCV infections among chronic hepatitis C patients in China

目的了解我国慢性丙型肝炎病毒(heptitis C virus,HCV)感染者中不同基因型/亚型HCV混合感染率以及影响因素,为制定适合我国国情的HCV预防和治疗政策提供科学依据。方法从全国各省(台湾省除外)的省会城市、直辖市(重庆市除外)和自治区(新疆除外)的三级甲等综合医院和传染病专科医院,随机收集2009-2011年HCV RNA阳性血浆(血清)标本1 450份,记录相应的年龄、性别、民族、籍贯、职业和病毒滴度等。分别以C/E1和NS5B为目的基因进行巢式PCR扩增并克隆测序。根据感染情况分为单独感染组和混合感染组,用χ2检验及t检验比较两组性别、年龄、民族和滴度等差异(P<0.05为差异有统计学意义)。结果 C/E1和NS5B两个基因PCR扩增均为阳性的标本1 159个,HCV混合感染者为11个,其余1 148个均为单独感染。不同基因型/亚型混合感染率为0.95%。混合感染的基因型涵盖了1b、2a和6a。1b+2a混合感染9个(2a占优势的6个,1b占优势的3个);6a+2a混合感染1个(6a占优势);6a+1b混合感染1个(6a占优势)。年龄、性别、民族和滴度等两组之间差异均无统计学意义。结论全国HCV不同基因型/亚型混合感染率为0.95%。混合感染的基因型涵盖了1b、2a和6a。6a基因型在中国慢性丙型肝炎患者的混合感染中首次被报道。

Objective To investigate the prevalence of mixed-genotype hepatitis C virus （HCV） infections and the as- sociation with various clinical risk factors among chronic hepatitis C patients in China. Methods A total of 1 450 HCV RNA （＋） serums were collected from 29 provinces of China. Reverse-transcription and polymerase chain reaction （RT- PCR） methods were performed using two different sets of primers, targeting the C/E1 and non-structural 513 region of the HCV genome. Resulting sequences were obtained by direct and cloning sequencing. Discrepancies in the results from phylogenetic analysis of both regions suggest mix infections. Gender and ethnics were examined between mixed infections and single-genotype infections by Chi-Square test, t-test was done to compare ages and HCV viral load. Results Of the 1 450 HCV infected patients, both C/E1 and NS513 sequences were obtained from 1 159 cases and among them, mix infections were detected from 11 （0. 95%）, single-genotype HCV infections were found in 1 148 cases. Nine patients were infected with mixed HCV subtype 1b and 2a, one with subtype 6a and 2a, one with subtype 6a and lb. There was no significant difference between mix infections and single-genotype infections by age, gender, ethnics and viral load. Conclusions The prevalence of mixed-genotypes HCV infections in China was 0. 95 %. The subtypes in mix infections were 1b, 2a and 6a. It is the first time that HCV subtype 6a infection was found in China.