The Molecular Epidemiological Study of HCV Subtypes among Intravenous Drug Users and Non-Injection Drug Users in China

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

INTRODUCTION

The treatment of hepatitis C has entered the pan-genotypic era, but the effectiveness is not good for the genotype 3b patients who have a large proportion in China. The guidelines for hepatitis C recommend the use of gene-specific regimens when the regional 3b prevalence rate greater than 5%. This study is to explore rationality of this proportion and the cost-effectiveness to implement pan-genotypic regimens in China.

METHODS

A decision Markov model was developed from the health system perspective to evaluate the effectiveness and cost-effectiveness between pan-genotypic and gene-specific treatment regimens for hepatitis C patients. Additionally, we set a regional genotype 3b patient proportion of 0-100% to explore at which proportion it is necessary to perform genotype identification and typing therapy on patients. Model parameters were derived from published literature and public databases. Effectiveness was measured by cured patient numbers, newly diagnosed cases of decompensated cirrhosis, hepatocellular carcinoma, need for liver transplantation, and quality-adjusted life years (QALYs). Cost-effectiveness outcomes included costs and the incremental cost-effectiveness ratio (ICER). The 1-3 times 2022 Chinese per capita gross domestic product was used as the willingness-to-pay threshold. One-way and probabilistic sensitivity analyses were performed to assess the uncertainty of the model parameters.

RESULTS

Compared with gene-specific regimens, pan-genotypic regimens resulted in an additional 0.13 QALYs and an incremental cost of $165, the ICER was $1,268/QALY. From the view of efficacy, the pan-genotypic regimens cured 5,868 more people per 100,000 patients than gene-specific regimens, avoiding 86.5% of DC cases, 64.6% of HCC cases, and 78.2% of liver transplant needs. Identifying 3b patients before treatment was definitely cost-effectiveness when their prevalence was 12% or higher. The results remained robust in sensitivity analyses.

CONCLUSIONS

In China, the prioritized recommendation of pan-genotypic therapeutics proves to be both cost-effective and efficacious. But, in regions where the prevalence of genotype 3b exceeds 12%, it is necessary to identify them to provision of more suitable therapies.

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

BACKGROUND

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.

AIM

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

METHODS

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.

RESULTS

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%).

CONCLUSION

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.

Direct-acting Antiviral Regimens for Patients with Chronic Infection of Hepatitis C Virus Genotype 3 in China

Hepatitis C virus (HCV) genotype (GT)3 infection is associated with a more rapid hepatic disease progression than the other genotypes. Hence, early HCV clearance slows down the disease progression and is important for improving prognosis in GT3-infected patients. Nevertheless, compared with other genotypes, GT3 is difficult-to-treat with direct-acting antivirals, especially in the presence of cirrhosis. Current guidelines recommend several regimens which have been proven to be effective in GT3-infected patients from the Western world (North America, Europe, and Oceania). In China, GT3 infection comprises 8.7-11.7% of the 10 million patients infected with HCV and has strikingly different characteristics from that in Western countries. Unlike the Western countries, where GT3a is the predominant subtype, GT3a and 3b each affect roughly half of Chinese GT3-infected patients, with 94-96% of the GT3b-infected patients carrying A30K+L31M double NS5A resistance-associated substitutions. Phase 3 clinical trials including GT3b-infected patients have suggested that GT3b infection is difficult to cure, making the regimen choice for GT3b-infected patients an urgent clinical gap to be filled. This review includes discussions on the epidemiology of HCV GT3 in China, recommendations from guidelines, and clinical data from both Western countries and China. The aim is to provide knowledge that will elucidate the challenges in treating Chinese GT3-infected patients and propose potential solutions and future research directions.

Risk of hepatitis C virus infection in injecting and noninjecting drug users receiving opioid substitution therapy

BACKGROUND

Hepatitis C virus (HCV) is the most common viral infection among illicit drug users in the world. Although intervention of needle and syringe program and opioid substitution therapy had engaged to prevent HCV infection, the prevalence of HCV infection does not seem to decline. The aim of this study was to estimate the risk of HCV infection in injecting drug users (IDUs) and noninjecting drug users (NIDUs) receiving opioid substitution therapy.

METHODS

We recruited 1179 heroin-dependent patients (age: 20-66 years) under opioid substitution therapy from 2012 to 2015 in a Psychiatric Center, Southern Taiwan. The data of HCV, hepatitis B virus and HIV infection and liver biochemical examination were obtained. We used multivariate logistic regression analysis to predict the risk of HCV infection.

RESULTS

There were 93.1% of IDUs and 68.1% of NIDUs positive for HCV infection. In IDUs, HIV infection, age of heroin initiation, duration and dose of heroin use, frequency of detoxification, and number of criminal conviction were significantly associated with HCV infection. In NIDUs, snort/sniff heroin exhibited a significantly increased risk of HCV infection. Intravenous injecting (odds ratio [OR] = 23.10, 95% CI = 8.04-66.40, p < 0.001), intravenous injecting combined snort/sniff (OR = 12.95, 95% CI = 3.90-42.97, p < 0.001), and snort/sniff (OR = 4.14, 95% CI = 1.30-13.18, p = 0.016) were significantly associated with increased risk of HCV infection compared with smoking. The trend was significant (p for trend <0.001).

CONCLUSION

In Taiwan, IDUs had harmful characteristics compared with NIDUs and both had extremely high prevalence of HCV infection. We provided evidence that snort/sniff is a possible way of leak in HCV infection despite needle-syringes supplement program been provided. Opioid substitution therapy program should include HCV assessment and treatment in the new direct-acting antiviral therapy era.

Complicated HCV subtype expansion among drug users in Guangdong province, China

Guangdong Province is one of the most developed and populous provinces in southern China. The subtype situation of hepatitis C virus (HCV) in Guangdong remains unknown. The aim of this study was to investigate and estimate the HCV subtypes in drug users (DU) using a city-based sampling strategy to better understand the characteristics of HCV transmission in Guangdong. Archived plasma samples (n = 1074) from DU who were anti-HCV positive in 2014 were selected randomly from 20 cities in Guangdong Province. Subtypes were determined based on core and/or E1 sequences using phylogenetic analysis. The distributions of HCV subtypes in DU and different regions were analyzed. A total of 8 genotypes were identified. The three main HCV subtypes in DU in Guangdong were 6a (63.0%), 3a (15.2%), and 3b (11.8%). Significant differences were discovered among different registered residency and regions but not among genders, marital status, education level, or drug use patterns. HCV subtype 3b was significantly higher in Guangdong residents than in non-Guangdong residents. In contrast, HCV subtype 6a was significantly lower in Guangdong residents than in non-Guangdong residents. Subtype 1b in eastern Guangdong (eastern) was significantly lower, while 6a was significantly higher when compared with other regions. Subtype 3a in the Pearl River Delta (PRD) region was significantly higher, while 3b was significantly lower when compared with other regions. In western Guangdong, HCV subtype 3a was significantly lower when compared with other regions. Additionally, in northern Guangdong subtypes 1b and 3b were significantly higher, while 6a was significantly lower when compared with other regions. Our study revealed the diversity and distribution of HCV subtypes in DU in nearly all the cities in Guangdong. The results provide essential information that will allow the establishment of specific intervention strategies that may help prevent HCV transmission.

Hepatitis C virus genotype diversity and distribution among methadone maintenance treatment patients in Jiangsu, China

BACKGROUND

Heroin users are vulnerable and represent a highly-infected reservoir for hepatitis C virus (HCV) infection. This study investigated HCV prevalence and genotypes distribution among heroin users who received methadone maintenance treatment (MMT) in Jiangsu.

METHODS

From June to December in 2016, a total of 534 patients among nine MMT clinics in six regions of Jiangsu were enrolled, with their demographic characteristics collected and serum samples tested for HCV antibody. 395 samples were seropositive and furthered to RNA extraction. HCV NS5B region fragments were amplified and subsequently sequenced.

RESULTS

Among HCV seropositive samples, 240 were characterized by NS5B partial sequences and classified into four genotypes (GPs) and eight subtypes. HCV GP3 predominated and accounted for 66.3%, followed by GP1 (27.5%), GP6 (4.2%) and GP2 (2.1%). HCV subtypes 3b (41.7%) and 3a (24.6%) were the most common subtypes. None of the demographic characteristics showed a significant difference when comparing with HCV genotypes. The geographic feature shown GPs in six regions were the same, but the frequency of subtypes exhibited regional divergence. Phylogenetic analyses demonstrated that 3b had become a local endemic in Jiangsu.

CONCLUSION

The distribution of HCV subtypes among heroin users in Jiangsu province was complex. The data could provide more precise estimates for HCV prevalence and genotype distribution as well as heroin users of Jiangsu province.

Hepatitis C Virus Subtype and Evolution Characteristic Among Drug Users, Men Who Have Sex With Men, and the General Population in Beijing, China

The aim of this study was to characterize the current molecular epidemiology of hepatitis C virus (HCV) infection and evaluate the evolutionary patterns of HCV subtypes in Beijing, China, among different subpopulations.The whole blood samples and behavioral data were collected from a total of 10,354 subjects, including drug users (DUs), men who have sex with men (MSM), and the general population, in Beijing from 2010 to 2011. Samples were tested for HCV infection using both enzyme-linked immunosorbent assay (ELISA) and real-time PCR. All viremic subjects were then sequenced by nested PCR over core/E1 and NS5B regions. Phylogenetic and phylogeographic analysis was performed by BEAST software.In total, 217 subjects (2.1%) were tested positive for HCV by antibody or vRNA-based testing. HCV prevalence rates for DUs, MSM, and the general population were 26.2%, 0.54%, and 0.37%, respectively. The 156 HCV RNA-positive samples were sequenced. Nine HCV genotypes, including 1a, 1b, 2a, 3a, 3b, 6a, 6n, 6u and 6v, were detected. The most prevalent subtypes were 3b (36.09%), 1b (32.54%), and 3a (16.57%). Bayesian evolutionary analysis estimated that the time of introduction of subtype 1b into Beijing was 2004 (95% CI: 1997.7, 2007.7), with subtypes 3a and 3b being introduced later in 2006. Evolutionary analyses further suggested that subtype 1b from Beijing and Shanghai were closely related, whereas subtype 3a sequences were more similar with sequences from Yunnan, Guangzhou, Hong Kong, and Jiangsu. Subtype 3b sequences were closely related to those from Yunnan, Guangdong, and Hong Kong.Thus, the current HCV epidemic in Beijing is complex, heavily affecting DUs, and involving multiple genotypes that likely spread from different regions in China with its large migrant population.