Distribution and changes in hepatitis C virus genotype in China from 2010 to 2020

Hepatitis C virus (HCV) causes a large number of infections worldwide. New infections seem to be increasing according to a report of the World Health Organization in 2015. Although direct-acting antivirals are quite effective for most genotypes of the HCV, some genotypes fail to respond. Therefore, the trend of genotype distribution is vital to better control the development of this infection.

To analyze the distribution and trends of the HCV genotype before and after the emergence of direct-acting antivirals in China.

We searched all literature published in five electronic databases-China National Knowledge Infrastructure, Wan Fang Data, VIP Chinese Journal Database, Chinese Biomedical Literature Service System, and PubMed-from January 1, 2010 to December 31, 2020. The search strategy combined medical subject headings and free-text terms, including "hepatitis C virus" or "HCV" and "genotype" or "subtype" and "China" or "Chinese". Additional relevant articles were searched by manual selection. Data were extracted to build a database. All of the data were totaled according to regions, periods, routes of transmission, and sexes. The percentages in various stratifications were calculated.

There were 76110 samples from 30 provinces included in the study. Genotype 1 (G1) accounted for 58.2% of cases nationwide, followed by G2, G6, G3b, G3a, unclassified and mixed infections (17.5%, 7.8%, 6.4%, 4.9%, 1.8%, and 1.2%, respectively). The constitution of genotype varied among different regions, with G6 and G3b being more common in the south and southwest, respectively (28.1%, 15.4%). The past ten years have witnessed a decrease in G1 and G2 and an increase in G3 and G6 in almost all regions. The drug-use population had the most abundant genotypes, with G6 ranking first (33.3%), followed by G1 and G3b (23.4%, 18.5%).

G3 and G6 pose a new challenge for HCV infection. This study revealed the distribution of HCV genotypes in China over the past 10 years, providing information for HCV management strategies.