Different hepatitis B virus genotype distributions among asymptomatic carriers and patients with liver diseases in Nanning, southern China.

To determine the hepatitis B virus (HBV) genotype distribution among asymptomatic carriers and patients with liver diseases in Nanning, China, where the prevalence of HBV infection is high, the serum samples from 39 asymptomatic HBV carriers and 103 liver diseases patients were examined for the presence of HBV DNA by polymerase chain reaction and for genotypes by restriction fragment length polymorphism analysis. All patients were positive for HBV DNA and 135 (95.1%) patients were classified by RFLP, the remaining seven were classified by sequencing. Finally, six (4.2%), 20 (14.1%), 113 (78.9%) and two (1.4%) patients were identified with genotype A, B, C and D, respectively. One (0.7%) case was confirmed to be co-infected with both genotypes B and C. Genotype C was more frequently observed in cases with advanced liver diseases and relatively less frequently in case with mild liver diseases. In contrast, genotype B showed an opposite distribution pattern, although there was no statistically significant difference (P=0.05). The rate of positivity for anti-HBe was higher, but that for HBeAg was lower in chronic infection patients with genotype B than in those with genotype C, (P<0.05, P<0.05, respectively). Severe liver damage was observed in patients with genotype C compared with those with genotypes A or B (P<0.01, P<0.01, respectively). These results suggest that (1) genotype C is the predominant genotype in Nanning, China, (2) genotype C maybe more associated with development of severe liver diseases than genotype B.