A study on genotype prevalence of hepatitis B virus in Chengdu area

Objective To investigate the prevalence of hepatitis B virus(HBV) genotypes in patients with chronic HBV infection in Chengdu area of China in combination of two different assays. Methods The HBV S gene fragment was amplified by long and accurate PCR (LA-PCR) in 90 serum samples of positive patients and then sequenced for HBV genotyping. HBV genotyping was also studied with typespecific-primered PCR. The re- sults from the two methods were compared to certify their credibility and accuracy. Results Genotype B was de- tected in 63.3% (57/90) of subjects by sequencing S fragment, genotype C in 33.3% (30/90), genotype D in 3.3% (3/90). None of any other genotypes in this group of patients was detected. However, mixed-genotype in- fection was detected in 25.5% (23/90) of subjects by genotyping following PCR with typespecific primers. Conclu- sion HBV genotype B was the predominant genotype in Chengdu area while genotype C was secondary, and geno- type D was singularly. S fragment sequencing was believed better in genotyping HBV, which described diversity of HBV quasispecies.