STUDY OF HEPATITIS-C VIRUS GENOTYPE IN GUIZHOU AREA OF SOUTHWESTERN CHINA

Objective To determine the concordance in various hepatitis C (HCV) ge notyping methods and to investigate the distribution of HCV genotypes in Guizhou area of Southwest China. Methods Serum samples from 206 pat ients (100 with chronic hepatitis and 106 with hemopathy) were detecte d for antibody of HCV by second generation enzyme-labelled immunosorbe nt assay (ELISA). Thirty-five anti-HCV positive samples were detected for HCV RNA by RT-polymerase chain reaction (PCR) and 30 HCV RNA posit ive samples were determined for their genotypes by three various genot yping methods [PCR with type-specific primers at the core region (prim er-set), slot-blot hybridization with type-specific probes at NS5B reg ion (blotting) and the restric fragment length polymorphism analysis o f PCR products of 5'NC region (RFLP)]. Ten samples with the known geno type were analysed by the direct sequencing. Results Of 30 samples wit h positive HCV RNA, the types of 22 could be classified by three metho ds, and the genotypes determined by various methods had complete conco rdance. The types of 6 samples could be classified by two methods and 5 had agreement subtypes. The types of two samples could be classified only by RFLP. Overall, 27 (90.0%) had subtype Ib infection and 3(10.0 %) had subtype 2a infection. The nucleotide sequence of 8 samples with subtype Ib and one with subtype 2a were analysed by the direct sequen cing. The subtypes determined by sequence analysis were in complete co ncordance with those decided by various genotyping methods. Conclusion s Subtype Ib is the predominent HCV genotype in Guizhou area, while su btype 2a is less common. There was a good concordance with the genotyp ing results obtained by various HCV genotyping methods.