Department of Virology, Medunsa Campus, University of Limpopo/NHLS Dr George Mukhari Tertiary Laboratory, Pretoria, South Africa.
J Med Virol. 2012 Apr;84(4):601-7. doi: 10.1002/jmv.23215.
Hepatitis C virus (HCV) genotype is an important predictor of disease progression and treatment response. This descriptive study investigated the sequence diversity and genotypes of HCV in South Africa based on comparative analysis of the 5' untranslated region (UTR), C/E1, and NS5B regions of 60 sequences from 52 patients. Genotype distribution in the studied population was as follows: 54% (28/52) were genotype 5, 19% (10/52) were genotype 1, 19% (10/52) were genotype 4, and 2% (1/52) were genotype 3. Three of 52 (6%) individuals were infected with multiple genotypes based on the 5'UTR. Phylogenetic analysis of the 5'UTR was accurate in determining genotypes, while the C/E1 and NS5B coding region was able to differentiate both genotypes and subtypes, including an outlier group. Furthermore, this study observed the existence of distinct variants of HCV which were divergent from confirmed genotype 4 subtypes. For the first time in South Africa, this analysis has shown the presence of HCV subtypes 4k, 4q, and 4r, as well as evidence of intragenotypic recombinant 4l/4q within NS5B. In conclusion, while genotype 5a remains the predominant genotype in South Africa, the current study indicates the introduction of new subtypes and existence of variants of genotype 4 in South Africa.
丙型肝炎病毒 (HCV) 基因型是疾病进展和治疗反应的重要预测因素。本研究通过对 52 名患者的 60 个序列的 5'非翻译区 (UTR)、C/E1 和 NS5B 区进行比较分析，对南非 HCV 的序列多样性和基因型进行了研究。在所研究的人群中，基因型分布如下：54%（28/52）为基因型 5，19%（10/52）为基因型 1，19%（10/52）为基因型 4，2%（1/52）为基因型 3。基于 5'UTR，52 名个体中有 3 名（6%）感染了多种基因型。5'UTR 的系统进化分析在确定基因型方面是准确的，而 C/E1 和 NS5B 编码区能够区分基因型和亚型，包括一个异常组。此外，本研究观察到 HCV 存在明显的变异体，与已确认的基因型 4 亚型存在差异。这是南非首次分析出 HCV 亚型 4k、4q 和 4r 的存在，并在 NS5B 中存在基因型 4l/4q 的内基因重组证据。总之，虽然基因型 5a 仍然是南非的主要基因型，但目前的研究表明南非存在新的亚型和基因型 4 的变异体。
