Hepatitis B virus genotype distribution among chronic hepatitis B virus carriers in Shanghai, China

Objective: Hepatitis B virus (HBV) genotype distribution is still unclear i n China, where a high prevalence of HBV infection exists, although it is we ll known that HBV can be classified into six genotypes based on intergroup divergence. The aim of this study was to investigate the epidemiological di stribution of HBV genotypes and to clarify further the genotype-related dif ferences in the pathogenicity of HBV. Methods: Seminested PCR and restricti on fragment length polymorphism analysis were conducted in 97 asymptomatic HBV carriers (ASC) and 46 chronic hepatitis (CH), 37 liver cirrhosis (LC) a nd 44 hepatocellular carcinoma (HCC) patients in Shanghai, China. Results: Two hundred and twenty samples (98.2%) were positive for HBV DNA, and of th ese, 3 (1.4%), 38 (17.2%) and 179 (81.4%) were classified as genotype A, B and C, respectively. There was a statistically significant difference in th e distribution of genotypes B and C among various categories of liver disea ses (p < 0.01). The distribution of genotype C showed an increasing trend f rom ASC, CH and LC to the HCC group; in contrast, the distribution of genot ype B showed a decreasing trend in the same order. HBeAg positivity was hig her in genotype C than in genotype B in all the subjects or in the ASC grou p alone (p < 0.05, p < 0.01, respectively). More severe liver damage and a higher mean age were observed in genotype C than in genotype B (p < 0.01, p < 0.05, respectively). Conclusions: These results indicate the following: (1) genotypes A, B and C of HBV exist in Shanghai, China; (2) genotype C is the major genotype in this area; (3) genotype C is associated with the dev elopment of severe liver diseases, and (4) genotype B has a relatively good prognosis. Copyright (C) 2001 S. Karger AG, Basel.