Methodological Establishment And Preliminary Application Of Hepatitis C Virus Genotyping

BackgroundHepatitis C virus (HCV), which is mainly transmitted via blood, can cause hepatitis C which is a world-wide infectious disease. The overall infection rate of HCV was approximately 2%. HCV genotyping is one of those methods to know about the virus. On one hand, the treatment of hepatitis C should bake into consideration the genotyping results of HCV. The sensitivity and prognosis of combination therapy of ribavirin and interferon differ among the six genotypes. Thus genotyping of HCV will be included to optimize the course of treatment. On the other, the molecular epidemiological study of HCV is essential to get knowledge of transmission profile of HCV, thus benefiting the surveillance and intervention of HCV. Therefore, it is of great epidemiological and clinical importance to build up a genotyping method and investigate the incidence and molecular epidemiology of HCV.ObjectThis study was aimed at build up an in-house PCR method for HCV genotyping. Based on the genotyping results and demographic data of samples collected from HIV sentinels, factors which might result in discrepant distribution of HCV genotypes in a certain population will be studied. The difference of genotypic distribution in different areas or population will be studied as well.MethodsThe sequence of HCV of various genotypes (mostly those frequently found in China, that is, lb,2a,3a,3b,6a) from China (Beijing, Jiangxi, Hunan, Guangxi in pariticular) were collected and primers for NS5B were designed in accordance. A panel of 22 samples were amplified to access the efficiency of pimers. The qualified pimers were used to amplify the HCV-antibody-positive samples collected. The amplification mixture was sent for sequencing. The obtained sequence were used for phylogenetic analysis with the selected model. Then the phylogenetic information was analysed with demographic information. Chi-square test was used for analysis of categorical data.ResultsA set of primers containing two pairs were selected which could amplify 20 samples out of 22 samples. In this study 1315 samples were collected from Jiangxi, Guangxi, Hunan and Beijing. Two hundred and twenty-five sequences were obtained, 135 from Guangxi,22 from Beijing,22 from Jiangxi,46 from Hunan. The genotypic information was as follows:Guangxi 1a 6, 1b 38,3a 22,3b 14,6a 37,6e 2, samples unable to be genotyped 16; Hunan, 1b 2,3a 11,3b 16,6a 17; Beijing, 1b 15,2a 6a; Jiangxi, 1b 17,2a 5.ConclusionThe genotypic distribution of these four areas was different, 1b and 2a genotype still accounted for the majority of samples from Beijing and Jiangxi. In Guangxi and Hunan,6a became predominant in addition to 1b and 3a. Genotype 2 was rare in Hunan and Guangxi. Subtype 1b was also rare in Hunan.