Hepatitis C virus genotype distribution in Southern China during 2015-2016

Objective To investigate the current distribution of hepatitis C virus (HCV) genotype in Southern China and to understand the HCV transmission and to infer its transmitting trend. Methods The HCV gene subtypes of 3 524 specimens from Southern China were detected and analyzed by polyonerase chain reaction (PCR)-fluorescence probe method or sequencing. The regular nested PCR and sequencing were used for the phylogenetic tree analysis when the fluorescence PCR inefficiently identifying virus isolates. Results Among 3 524 specimens, there were 2 922 cases from Guangdong, 78 cases from Fujian, 152 cases from Hainan and 372 cases from Guangxi. Genotype 1b comprised the majority (1 808/3 524, 51.3%), followed by genotype 6a (925/3 524, 26.2%), 2a (298/3 524, 8.46%), 3a (246/3 524, 6.98%), 3b (200/3 524, 5.68%) and 1a (27/3 524, 0.77%). In addition, 1 case was genotype 6e, 1 case was genotype 6q, 1 case was genotype 6r, 3 case were genotype 6w, 2 case were genotype 6xa, 2 case were genotype 6n, and 1 case was genotype 6 with unclassified subtype. The genotype 1b accounted for the majority in most areas of 21 cities and counties in Guangdong Province, followed by genotype 6a. But in some areas, the major genotype was genotype 6a, followed by 1b. Genotype 4, genotype 5 and genotype 7 were not found in this study. Conclusions In the past two years, genotype 1b and 6a are still the epidemic genotypes in Guangdong, Guangxi and Hainan provinces. However, genotype 6a has replaced 1b as the dominant one in some areas in Guangdong Province. The distributions of HCV genotypes do not change significantly in Guangxi and Fujian provinces. Key words: Southern China; Hepatitis C virus; PCR- fluorescent probe method; Genotype distribution; Phylogenetic tree