Lack of geographical and ethnic distribution of Hepatitis B virus genotypes in Hainan Island, China.

Recent studies showed that the distribution of hepatitis B virus (HBV) genotype exhibited geographical and ethnic characteristics. Haikou city is the largest city on Hainan Island that geographically isolated from mainland of China, and is the home of multiple ethnic groups. The aim of the study was to investigate the characteristics of the HBV genotype/subgenotype distribution in Haikou city. HBV DNA was isolated from180 serum samples derived from the Han and Li groups. The HBV genotype was detected by polymerase chain reaction using genotype-specific primers and was further determined by full-length genome sequences. The results revealed that the genotype B (37.2%) and C (62.8%) were the predominant HBV genotypes in Haikou, regardless of ethnic background., Additionally, the genotype distribution was not significantly different regarding ethnicity, sex or level of serum HBV DNA. Moreover, there were multiple subgenotypes circulating in the region. In conclusion, our study revealed the diverse HBV genotypes/subgenotypes in Haikou. These findings provide a preliminary study of the distribution of HBV genotypes circulating on Hainan Island.