Molecular epidemiology of hepatitis C virus genotypes in different geographical regions of Chinese mainland and a phylogenetic analysis

Abstract

Background Hepatitis C virus (HCV) infection remains a major public health problem in Chinese mainland. Investigation of the distribution of genotypes contributed to the prevention, diagnosis and treatment of HCV infection. Therefore, we conducted a study on the distribution of HCV genotypes and phylogenetic analysis to provide an up-to-date understanding of the molecular epidemiology of genotypes in Chinese mainland. Methods Our retrospective multicenter study enrolled 11,008 samples collected between August 2018 and July 2019 from 29 provinces/municipalities (Beijing, Hebei, Inner Mongolia, Shanxi, Tianjin, Gansu, Ningxia, Shaanxi, Xinjiang, Heilongjiang, Jilin Liaoning, Henan, Hubei Hunan, Anhui, Fujian, Jiangsu, Jiangxi, Shandong, Shanghai Zhejiang, Guangdong, Guangxi, Hainan, Chongqing, Guizhou, Sichuan and Yunnan). Phylogenetic analysis of each subtype was performed to infer the evolutionary relationship of sequences from diverse regions. Two independent samples t tests were used for the comparison of continuous variables, and chi-square tests were used for the comparison of categorical variables. Results Four genotypes (1, 2, 3 and 6) were found, including 14 subtypes. HCV genotype 1 was dominant, accounting for 49.2%, followed by genotypes 2, 3 and 6, accounting for 22.4%, 16.4%, and 11.9%, respectively. Additionally, the top five subtypes were 1b, 2a, 3b, 6a and 3a. Proportions of genotypes 1 and 2 decreased while genotypes 3 and 6 increased over past years (P < 0.001). Genotypes 3 and 6 were concentrated in the population aged 30 to 50 years, and male carriers had lower proportions of subtypes 1b and 2a than female carriers (P < 0.01). Genotypes 3 and 6 were more prevalent in southern parts of Chinese mainland. Nationwide spreads of subtypes 1b and 2a were associated with sequences from northern parts of Chinese mainland, while subtypes 3a, 3b and 6a were associated with sequences from southern parts of Chinese mainland. Conclusions HCV subtypes 1b and 2a remained the most common subtypes in Chinese mainland, and their proportions decreased over the past years, while the proportions of genotypes 3 and 6 increased. Our investigation provided an accurate epidemiological picture of the circulating viral strains in Chinese mainland, contributing to the prevention, diagnosis and treatment of HCV infection. Trial registration: Not applicable.

Hepatitis C virus subtype diversity and transmission clusters characteristics among drug users in Zhuhai, South China

“…In our study, we found that the predominant HCV subtypes among drug users in Zhuhai, a port city in Guangdong Province in China, were 6a (60.26%), followed by 3b (16.7%) and 3a (12.8%), respectively. This predominance of the 6a subtype in Zhuhai is consistent with previous reports, as 6a was mainly prevalent in South China, like the Guangdong and Guangxi provinces [ 9 , 31 ]. The genotype GT3 (3a and 3b) primarily circulated in Southwest China, like Yunnan province, and East Asian countries, where drug smuggling and intravenous drug abuse were prevalent [ 9 , 31 – 33 ].…”

“…This predominance of the 6a subtype in Zhuhai is consistent with previous reports, as 6a was mainly prevalent in South China, like the Guangdong and Guangxi provinces [ 9 , 31 ]. The genotype GT3 (3a and 3b) primarily circulated in Southwest China, like Yunnan province, and East Asian countries, where drug smuggling and intravenous drug abuse were prevalent [ 9 , 31 – 33 ]. Surprisingly, the prevalence of genotype GT3 was also remarkably high among drug users in Zhuhai, reaching approximately 30%.…”

“…Hepatitis C Virus exhibits a broad global distribution, with significant regional variations in genotype prevalence [ 17 , 18 ]. China has recorded six genotypes and 24 subtypes to date, with the subtypes 1b and 2a being the most predominant [ 9 , 31 ]. In our study, we found that the predominant HCV subtypes among drug users in Zhuhai, a port city in Guangdong Province in China, were 6a (60.26%), followed by 3b (16.7%) and 3a (12.8%), respectively.…”

Transmission Network of Hepatitis C Virus Subtype 2a in Huazhou County, Shaanxi Province, China

“…Subtype 2a, once predominantly transmitted through contaminated blood transfusions prior to the 1900s, has seen a decline in prevalence after the 1992 ban on paid blood donations, but it remains to be one of the most prevalent subtypes alongside subtype 1b. Conversely, subtypes 3a, 3b, and 6a, associated with injection drug use, have increased, according to recent studies [12]. Shaanxi province had less diversi ed genotype distribution patterns compared to southern Chinese provinces, with subtype 2a being particularly prevalent [5,[12][13].…”

Is it time for China to prioritize pan-genotypic regimens for treating patients with hepatitis C?

“…While nosocomial transmission is now effectively controlled, the challenges persist in controlling transmission among individuals engaged in drug use and those involved in high-risk sexual behaviors [ 11 , 12 ]. The majority of this population is infected with subtypes 3 and 6 [ 13 – 15 ], signifying that patients with genotype 3b will account for an increased proportion of patients with hepatitis C in the future [ 16 ]. Using pan-genotypic regimens may not be the best choice for 3b patients, but the process of identifying these patients imposes time and testing costs on non-3b patients.…”