Increased prevalence of hepatitis C virus subtype 6a in China: a comparison between 2004-2007 and 2008-2011

HCV 6a was expanding and became the predominant subtype among blood donors between 2004 and 2019 in Guangdong, China

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Currently, HCV 6a has replaced 1b as the most prevalent subtype in blood donors in Guangdong.

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HCV 6a was the predominant subtype in males and older donors, while 1b predominated in females and younger donors.

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HCV 6a may expand from Guangdong to other districts of China, and is worthy of attention.

The Transmission Route and Selection Pressure in HCV Subtype 3a and 3b Chinese Infections: Evolutionary Kinetics and Selective Force Analysis

Hepatitis C virus (HCV) genotype 3 (GT-3) represents 22–30% of all infections and is the second most common genotype among all HCV genotypes. It has two main subtypes, GT-3a and GT-3b, that present epidemiological differences in transmission groups. This report generated 56 GT-3a and 64 GT-3b whole-genome sequences to conduct an evolutionary kinetics and selective force analysis with reference sequences from various countries. Evolutionary analysis showed that HCV GT-3a worldwide might have been transmitted from the Indian subcontinent to South Asia, Europe, North America and then become endemic in China. In China, GT-3a may have been transmitted by intravenous drug users (IDUs) and become endemic in the general population, while GT-3b may have originated from IDUs and then underwent mutual transmission between blood donors (BDs) and IDUs, ultimately becoming independently endemic in IDUs. Furthermore, the spread of GT-3a and GT-3b sequences from BD and IDU populations exhibit different selective pressures: the proportion of positively selected sites (PPSs) in E1 and E2 from IDUs was higher than in BDs. The number of positive selection sites was higher in GT-3b and IDUs. These results indicate that different selective constraints act along with the GT-3a and GT-3b genomes from IDUs and BDs. In addition, GT-3a and GT-3b have different transmission routes in China, which allows us to formulate specific HCV prevention and control strategies in China.

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.

Complete genome sequencing and evolutionary analysis of hepatitis C virus subtype 6a, including strains from Guangdong Province, China

We performed an evolutionary analysis using whole genome sequence isolates of hepatitis C virus (HCV) 6a from Guangdong Province and reference sequences from various countries. Less than 5% of the HCV genome was found to be under positive selection. The E1 and E2 proteins had the highest proportion of positively selected sites both within and outside of CD8 T cell epitopes in all of the strains. Regions corresponding to CD8 T cell epitopes were under negative selection except in the isolates from Guangdong. Furthermore, we found evidence of three introductions of the virus into Guangdong from Vietnam and other Southeast Asian countries. Thus, this study provides information about the transmission of HCV 6a by comparison of full-length sequences, indicating the impact of selective constraints in Guangdong and across China.

The distribution of hepatitis C virus infection in Shanghai, China: a time-spatial study

BACKGROUND

Shanghai, as a pilot city of China to achieve the goal of eliminating hepatitis C, its strategy of allocating medical resources is a pressing problem to be solved. This study aims to infer the time-spatial clustering patterns of HCV-infected cases, and grasp the dynamic genotype distribution of HCV, thereby inform elimination strategies of HCV with efficacy and efficiency.

METHODS

Reported HCV cases including their demographic information in Shanghai city from 2005 to 2018 were released from the National Infectious Disease Reporting Information System, population data at community scale, geographical layers of hospitals, communities and districts were gathered from former research. Blood samples of HCV-infected individuals were collected during 2014-2018 from 24 sentinel hospitals, HCV-antibody test, qualitative nucleic acid test and NS5B/5'UTR gene amplification were performed accordingly to determine the genotypes of the specimen. Furthermore, global and local spatial self-correlation analysis of both acute and chronic HCV infections were conducted at community scale year by year, then time-spatial clusters of acute and chronic HCV infections and HCV genotype distribution of specimen collected from sentinel hospitals by districts were mapped by using Arcmap10.1.

RESULTS

A total of 2631 acute HCV cases and 15,063 chronic HCV cases were reported in Shanghai from 2005 to 2018, with a peak in 2010 and 2017, respectively. The mean age of chronic HCV patients was 49.70 ± 14.55 years, 3.34 ± 0.32 years older than the acute (t = 10.55, P-value < 0.01). The spatial distribution of acute HCV infection formed one primary cluster (Relative Risk = 2.71), and the chronic formed one primary cluster and three secondary clusters with Relative Risk ranged from 1.94 to 14.42, meanwhile, an overlap of 34 communities between acute and chronic HCV clusters were found with time period spans varied from 6 to 12 years. Genotype 1 (N = 257, 49.71%) was the most prevalent HCV genotype in Shanghai, genotype 3 infections have increased in recent years. Baoshan district presented cluster of acute HCV and the highest proportion of genotype 2, Pudong new area was the cluster of chronic HCV and occupied the highest proportion of genotype 3.

CONCLUSIONS

Despite the low prevalence of HCV infection, it is still needed to push forward the elimination process in Shanghai, as there is a certain amount of HCV infected people waiting to be treated. The time-spatial clustering patterns and the dynamic of HCV genotype distribution together indicated a changing constitution of different transmission routes of HCV infection, thus, a focused strategy may be needed for high-risk population related to genotype 3 infection like drug users, in addition to an enforcement of the existing measures of preventing the iatrogenic and hematogenic transmission of HCV.

How would China achieve WHO's target of eliminating HCV by 2030?

Introduction: Hepatitis C virus (HCV) infection is a major global health concern on the rise, prompting unprecedented efforts by the World Health Organization (WHO) to eliminate this epidemic by 2030. Being the country with the largest HCV-infected population in the world, China has been faced with a general lack of awareness for HCV, low treatment uptake and subpar collaborations among healthcare providers and stakeholders. Areas covered: This review discusses the epidemiological situations of HCV infection and the challenges in HCV management in China. This review also explores micro-elimination strategies in China, identifying potential sub-populations for concerted efforts in eliminating HCV. As DAAs are increasingly recognized as a more effective alternative to traditional regimens, the cost-effectiveness and budget impacts of bringing more DAAs into the reimbursement lists are also addressed. Several small-scale targeted literature searches were conducted in PubMed for various topics covered in the article, and hand searching was performed to fill any data gaps. More recent data were used wherever possible. Expert opinion: Considering the unique socioeconomical landscape of China, micro-elimination strategies might be more effective and should be targeted at high-risk populations. Varying regional needs in HCV care across the country necessitate decentralized approaches in research and policy-making.

HCV genotype 6 prevalence, spontaneous clearance and diversity among elderly members of the Li ethnic minority in Baisha County, China

The epidemiology of hepatitis C virus varies widely across geographical regions and ethnic groups. Our previous study showed that 6 strains isolated from Baisha County, Hainan Island, China, were all new genotype 6 (gt6) subtypes which differed significantly from subtypes of other regions. In the current study, we conducted a comprehensive epidemiological survey of HCV in the Li ethnic group, native to Baisha County. Anti-HCV antibodies were detected by 2 independent ELISAs in all participants, and positive results confirmed by the recombinant immunoblot assay (RIBA) and HCV RNA viral loads were measured. Univariate chi-square test and multivariable logistic regression analyses were used to determine the risk factors for HCV infection and spontaneous clearance rates. Indeterminate RIBA results were excluded or included in analyses; consequently, findings were expressed as a range. Direct sequencing of partial regions within NS5B and E1 was employed for genotyping. Among 1682 participants, 117 to 153 were anti-HCV positive (7.0%-9.1%), with 42.7%-52.6% confirmed to have cleared infection. Anti-HCV positivity was associated with older age (≥60 years) (OR = 0.02, 95% CI 0.01-0.05, P < 0.01) and surgery (OR = 2.75, 95% CI 1.36-5.57, P < 0.01), with no significant difference found between the HCV infection group and the HCV spontaneous clearance group. The gt6 subtype distribution characteristics of Baisha County were unique, complex and diverse. The sequences did not cluster with known gt6 subtypes but formed 4 Baisha community-specific groups. HCV infection in members of the Li minority ethnic group is characterized by high prevalence rates in the elderly, high spontaneous clearance rates and broad gt6 diversity.

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.

Epidemiology and management of hepatitis C virus infections in immigrant populations

BACKGROUND

At present, there is a continuous flow of immigrants from the south of the world to north-western countries. Often immigrants originate from areas of high-prevalence of viral hepatitis and pose a challenge to the healthcare systems of the host nations. Aims of this study is to evaluate the prevalence and virological and clinical characteristics of hepatitis C virus (HCV) infection in immigrants and the strategies to identify and take care of the immigrants infected with HCV.

MAIN BODY

We conducted an electronic literature search in several biomedical databases, including PubMed, Google Scholar, Scopus, Web of Science, using different combinations of key words: "HCV infection; chronic hepatitis C, immigrants; low-income countries". We included studies written in English indicating the epidemiological data of HCV infection in the immigrant population, studies that assessed the clinical presentation, clinical management and treatment with directly acting antiviral agent in immigrants, HCV infection is unevenly distributed in different countries, with worldwide prevalence in the general population ranging from 0.5 to 6.5%. In Western countries and Australia this rate ranges from 0.5 to 1.5%, and reaches 2.3% in countries of south-east Asia and eastern Mediterranean regions, 3.2% in China, 0.9% in India, 2.2% in Indonesia and 6.5% in Pakistan; in sub-Saharan Africa the prevalence of HCV infection varies from 4 to 9%. Immigrants and refugees from intermediate/high HCV endemic countries to less- or non-endemic areas are more likely to have an increased risk of HCV infection due to HCV exposure in their countries of origin. Because of the high HCV endemicity in immigrant populations and of the high efficacy of directly acting antiviral agent therapy, a campaign could be undertaken to eradicate the infection in this setting.

CONCLUSIONS

The healthcare authorities should support screening programs for immigrants, performed with the help of cultural mediators and including educational aspects to break down the barriers limiting access to treatments, which obtain the HCV clearance in 95% of cases and frequently prevent the development of liver cirrhosis and hepatocellular carcinoma.

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.

Genotype distribution of hepatitis C virus in 952 cases from 2014 to 2016 in Hunan Province, China

INTRODUCTION

Few large-scale investigations on genotype (GT) distribution of hepatitis C virus (HCV) in Hunan Province, China, are reported.

MATERIAL AND METHODS

We recruited all of the 952 patients in the census register of Hunan Province who were first diagnosed with HCV infection in the Second Xiangya Hospital, Central South University in 2014-2016. HCV genotypes were surveyed. The genotype distribution pattern was compared with those of the neighboring regions in China.

RESULTS

Among the 952 patients, genotype 1 (GT1) (69.9%) was the most common HCV genotype, followed by GT6 (19.0%), GT3 (8.4%), and GT2 (2.6%). GT4 and GT5 were not found. One case had mixed infection of GT3 and GT6. Predominance of GT1 HCV was more evident in the patients aged ≥ 40 years than in those aged < 40 years (79.5% vs. 47.9%, χ2 = 95.993, p < 0.001). HCV genotype distribution had gender difference (χ2 = 44.695, p < 0.001), with GT3 and GT6 more prevalent in males than in females (36.2% vs. 18.2%, χ2 = 39.088, p < 0.001) while GT1 more prevalent in females than in males (80.1% vs. 60.3%, χ2 = 44.276, p < 0.001). Though Hunan Province is located in central China, its HCV genotype priority was similar with the change trend in south and southwest China, while distinguished from those of other regions, in particular from the neighboring central province, Hubei Province.

CONCLUSIONS

HCV GT1 was the most predominant HCV genotype in Hunan Province, and GT6 and GT3 accounted for a significant percentage, especially in young patients. The HCV distribution pattern was more similar to those of the regions in south China.

Analysis of Transmission Routes of Hepatitis C Virus Based on Virus Genotyping in 341 Cases with Different Suspected Initial Infection Time Points in Hunan Province, China

Background

Few investigations have been reported on the changing trends in transmission routes of hepatitis C virus (HCV) and the corresponding HCV genotype (GT) distribution in Hunan province, China.

Material/Methods

HCV GTs, suspected viral transmission routes, and time of initial infections were investigated in 341 HCV-infected patients in 2016.

Results

Genotype 1 (GT1) (72.1%) was the most prevalent HCV GT, followed by GT6 (17.6%), GT3 (7.6%), and GT2 (2.6%). GT4 and GT5 were not found. The predominant HCV transmission routes were blood-related routes (57.5%) and intravenous drug use (IDU) (15.0%); 52.2% of the patients got HCV infection before 1994, 25.6% from 1994 to 1998, and 22.2% after 1998; 93.5% of the infections via blood-related transmission routes were with HCV GT1, 61.5% via IDU or feculent sexual contact were with HCV GT6, and 50.0% via non-healthcare invasive procedures were with HCV GT6. HCV infections via IDU or feculent sexual behavior were more prevalent in young males, while infections via invasive cosmetic procedures occurred more in young females, and both had a shorter time interval from suspected infection to confirmed clinical diagnosis. Multinomial logistic regression confirmed the time points of the initial HCV infections and suspected viral transmission routes were correlated with HCV GT distribution.

Conclusions

HCV GT1 infections via blood-related transmission routes in Hunan province have continually decreased since 1994. However, younger patients infected with HCV, especially with HCV GT6 via IDU, feculent sexual behavior, and non-healthcare invasive procedures, have significantly increased.

Molecular evolution of hepatitis C virus in China: A nationwide study

The evolutionary and epidemic history and the regional differences of hepatitis C virus (HCV) are complex and remain unclear in the vast territory China. Here we recruited 1540 HCV-RNA positive patients sampled in 29 provinces across whole China, which is the largest sample capacity and the most comprehensive geographic coverage of China to our knowledge. 1b, 2a, 3b, 6a and 3a were the major subtypes in China. 1b was the most predominant subtype which presented in every province. The second most predominant subtype, 2a, appeared to concentrate in the north of China. Subtypes 3a and 3b were mainly found in the Southwest region, while 6a was restricted in the South region. We further estimated the origins of the dominating subtypes and discovered for the first time that a Chinese-specific transmission pattern for some strains of subtype 2a which was restricted in north China, and Chinese subtype 3b originated from Thailand.

Prevalence of hepatitis C infection and its associated factors in healthy adults without identifiable route of transmission

While hepatitis C virus (HCV) infection is long known to be associated with parenteral exposure, the specific route of transmission is not identified in a proportion of infected patients. Taking blood donors as the surrogate of healthy adults in the community in Hong Kong, we identified 91 HCV-infected donors (≤0.02% positive rate) in 2014-2016, of whom 46 were recruited in a mixed-method study to examine their transmission routes. A majority (75%) of the recruited donors were HCV RNA positive, with the predominant subtypes being 1b and 6a. From the results of the structured self-administered questionnaire and in-depth interviews, only 14 (30%) recruited donors could be traced to past history of contaminated blood transfusion (n = 9) or injection drug use (n = 5). Case-control analyses with 3 different control groups were performed to examine factors associated with HCV infection in multivariable analyses. High-risk sexual behaviour, body piercing, intramuscular injection and vaccine inoculation abroad, having lived abroad for >3 months were significantly associated with HCV in donors with otherwise nonidentifiable source of infection. While the specific route of transmission cannot be established for each person, associations with multiple parenteral exposures outside Hong Kong were observed. The World Health Organization has advocated for the global elimination of HCV by 2030. With a high proportion of HCV-infected persons who are unaware of their infections, HCV elimination could be hard to achieve.

Naturally Occurring Resistance-Associated Variants to Hepatitis C Virus Direct-Acting Antiviral Agents in Treatment-Naive HCV Genotype 6a-Infected Patients

BACKGROUND AND OBJECTIVE

The direct-acting antiviral agents (DAAs) antiviral therapy has drastically improved the prognosis of hepatitis C virus (HCV) patients. However, the viral drug resistance-associated variants (RAVs) can limit the efficacy of DAAs. For the HCV-6a is not the predominant prevalent genotype; the data on the prevalence of naturally occurring RAVs in it is scarce. Our study aims to assess the prevalence of RAVs in treatment-naive HCV-6a patients.

METHODS

Nested PCR assays were performed on 95 HCV-6a patients to amplify HCV viral regions of NS3, NS5A, and NS5B.

RESULTS

In NS3/4A region, we detected Q80K in 95.5% isolates (84/88) and D168E in 2.3% isolates (2/88). In NS5A region, we detected Q30R in 93.2% isolates (82/88), L31M in 4.6% isolates (4/88), and H58P in 6.8% isolates (6/88). In NS5B region, we detected A15G in 2.3% isolates (2/88), S96T in 1.1% isolates (1/88), and S282T in 20.7% isolates (17/88) and we detected I482L in 100% isolates (4/4), V494A in 50% isolates (2/4), and V499A in 100% isolates (4/4).

CONCLUSIONS

RAVs to DAAs preexist in treatment-naive HCV-6a patients. Further studies should address the issue of the impact of RAVs in response to DAA therapies for HCV-6a patients.

Hepatitis B, C, and D virus infection showing distinct patterns between injection drug users and the general population

BACKGROUND AND AIM

Hepatitis B, C, and D virus (HBV, HCV, and HDV) infections are known to be prevalent in injection drug users (IDUs); however, the relationship between the molecular epidemiologic features of hepatitis virus infection in high-risk individuals and the general population has not yet been established.

METHODS

In total, 1049 IDUs and 672 individuals who underwent physical examinations at Chenzhou hospital, Hunan Province, China, were enrolled. HBV, HCV, and HDV infections were screened with serologic tests in both populations. HBsAg-positive, anti-HCV IgG-positive, and anti-HDV IgG-positive samples were further confirmed by polymerase chain reaction, quantitative polymerase chain reaction, and DNA sequencing.

RESULTS

Significantly higher HBV (21.54 vs 16.52%, P = 0.01), HCV (45.95% vs 1.34%, P < 0.001), and HDV (5.62% vs 0.30%, P < 0.001) infections were detected in IDUs compared with the general population. The dual infection of HBV/HCV or HBV/HDV was also significantly higher in IDUs than in the general population. HBV genotype B and HDV genotype II were dominants in both populations. HCV infection showed genotype 6a (49.52%) dominant in IDUs, but genotype 1b accounted for 50% infection, which was followed by genotype 6a (33.33%) in the general population. Higher viral loads were associated with HBV genotype B and HCV genotype 6a compared with non-dominant genotypic infections.

CONCLUSIONS

HBV and HDV infections shared similar patterns by IDUs and the general populations, and HCV infection exhibited distinct features between two populations. Our results suggest different molecular epidemiologic characteristics of HBV, HCV, and HDV infection in two populations.

Age and gender distribution of Hepatitis C virus prevalence and genotypes of individuals of physical examination in WuHan, Central China

Approximately 170 million people in the world are infected with Hepatitis C virus (HCV). There are no published population based studies about the prevalence of HCV genotypes and the associations of genotype and Infection frequency with gender and age in WuHan. We aimed to investigate the distribution of HCV prevalence and genotypes among different gender and age patients with chronic HCV infection in WuHan from 2011 to 2015. A total of 2685 anti-HCV positive serum samples from individuals of physical examinationwere recruited from the Renmin Hospital of WuHan University, Hubei Province in China from January 2011 to December 2015. From these 2685 anti-HCV positive serum samples, 496 samples were with a positive PCR for HCV RNA. The number of HCV infection showed an increase with year, but the annual infection rate has remained similar (χ² = 2.94, P = 0.568). 2685 cases were infected with HCV from 2011 to 2015 in WuHan city of China. Blood transfusion (18.14 %) was the main routs of transmission, followed by Surgery (8.94 %). The highest prevalence of HCV infection was at the age group 50–59 (25.85 % of 2685) and the lowest prevalence was 0–9 (0.93 % of 2685). HCV genotype 1 was the most prevalent (73.39 %), followed by genotypes 2 (17.14 %), 3 (5.25 %) and 6 (3.22 %). Genotype 4 and 5 was not detected in these patients. The most prevalent subtype was subtype 1b (71.98 %), followed by genotypes 2a (17.14 %). Five patients had mixed infection across the HCV subtypes. Among all genotypes, genotype 1 was highest in both male (73.27 %) and female (73.47 %) patients, followed by genotype 2. Genotype 1 (male: 29.84 % of 496, vs female: 43.55 % of 496, χ² = 20.07, P < 0.0001), genotype 2 (male: 6.25 % of 496, vs female: 10.89 % of 496, χ² = 6.81, P = 0.009), and 6 (male: 1.41 % of 496, vs female: 1.81 % of 496, χ² = 0.626, P = 0.401) were more common in female patients than males, while no significant gender differences were observed for genotype 6. Among age group 50–59 years Genotype 1 was most common in male patients (29.05 % of 148) followed in 20–29 years (23.65 % of 148), genotype 2 in the age group 60–69 (12 cases of 31) and genotype 3 in the age group 50–59 (4 cases of 13) and genotype 6 was most frequent in the age group 30–39 (4 cases of 7). The frequency of HCV prevalence was significantly higher in female patients compared to males before ages 60, while the opposite result was observed after 60 years. The most common HCV genotype in WuHan was subtype 1b followed by 2a and more common among women than males patients. Further studies are needed to collect a large number of samples to estimate the different epidemiology of the HCV genotypes, because the sample size of non-genotype 1b and 2a is not large enough and other factors like disease history/monthly income/etc. are not included in our study.

Changing Epidemiology of Hepatitis C Virus Genotype among Patients with Human Immunodeficiency Virus/Hepatitis C Virus Co-Infection in China

BACKGROUND

Co-infection with hepatitis C virus (HCV) has become the most common cause of death in human immunodeficiency virus (HIV) infected patients on antiretroviral therapy. The distribution of HCV genotypes varies with geographical regions and time, and limited studies have focused on the HCV genotype in HIV/HCV co-infection.

METHODS

The distribution of HCV genotypes was evaluated in 414 patients with HIV/HCV co-infection in three regions (South, Central and Northwest) of China from 2008 to 2010. The NS5B region of HCV was characterized using nested reverse transcription polymerase chain reaction. Nucleotide sequences obtained were subjected to phylogenetic analysis, and genotypes were assigned using published reference genotypes.

RESULTS

Genotype 3 was the most prevalent HCV strain (36.2%), followed by genotype 6 (30.0%), genotype 1 (28.5%), genotype 2 (5.1%), and genotype 5 (0.2%). The distribution varied geographically. Genotype 6 (37.6%) was the predominant strain while genotype 1 (20.2%) was less common in the South compared to the Central and Northwest regions (all P < 0.001). The distribution also varied temporally. There was no significant difference in genotype distribution in Guangdong (a province in the South region), between patient cohorts from 2005-2008 and 2009-2010. However, outside Guangdong, genotypes 3 and 6a became significantly more prevalent (22.4% vs.42.2%, P< 0.001; 8.0% vs. 19.8%, P = 0.004), and genotype 1 less prevalent (54.4% vs.26.6%, P< 0.001) over time.

CONCLUSION

The most dramatic shift in genotypic distribution was the movement of HCV genotypes 3 and 6a outside of Guangdong in HIV/HCV co-infected patients. This movement appeared closely associated with transmission via injected drug use.

Response to Pegylated Interferon Plus Ribavirin in Patients with Hepatitis C Virus Genotype 6a Infection from Guangdong and Guangxi Province of China

Aim. Our aim is to survey the treatment effect of PEG-IFN plus ribavirin in patients infected with HCV genotype 6a in Guangdong and Guangxi province of China and investigate best course of antiviral treatment for patients with HCV-6a infection. Methods. 515 eligible patients received subcutaneous 180 μg PEG-IFNα-2a or 1.5 μg/kg PEG-IFNα-2b once weekly plus oral ribavirin. Primary outcome was SVR by intention-to-treat analysis. Secondary outcome was RVR, cEVR, ETR, and relapse rate. Results. SVR in patients with HCV-6a infection treated for 48 weeks was comparable to that in patients with HCV-2/3 infection (80.9% versus 82.5%, p = 0.812) and higher than that in patients with HCV-1b infection (80.9% versus 67.2%, p = 0.014). ETR (98.9% versus 90.6%, p = 0.016), virological response at month 3 of end-of- treatment (88.8% versus 76.6%, p = 0.044), SVR (80.9% versus 65.6%, p = 0.032), and virological response at month 12 of end-of-treatment (76.4% versus 60.9%, p = 0.04) in patients with HCV-6a infection treated for 48 weeks were higher than those in patients with HCV-6a infection treated for 24 weeks. Conclusion. SVR in patients with HCV-6a treated for 48 weeks was comparable to that in patients with HCV-2/3 infection and higher than that in patients with HCV-1b infection; patients with HCV-6a infection treated for 48 weeks had a superior treatment response than patients treated for 24 weeks.

Multiple Introduction and Naturally Occuring Drug Resistance of HCV among HIV-Infected Intravenous Drug Users in Yunnan: An Origin of China's HIV/HCV Epidemics

Background

The human immunodeficiency virus 1 (HIV-1) epidemic in China historically stemmed from intravenous drug users (IDUs) in Yunnan. Due to a shared transmission route, hepatitis C virus (HCV)/HIV-1 co-infection is common. Here, we investigated HCV genetic characteristics and baseline drug resistance among HIV-infected IDUs in Yunnan.

Methods

Blood samples of 432 HIV-1/HCV co-infected IDUs were collected from January to June 2014 in six prefectures of Yunnan Province. Partial E1E2 and NS5B genes were sequenced. Phylogenetic, evolutionary and genotypic drug resistance analyses were performed.

Results

Among the 293 specimens successfully genotyped, seven subtypes were identified, including subtypes 3b (37.9%, 111/293), 3a (21.8%, 64/293), 6n (14.0%, 41/293), 1b (10.6%, 31/293), 1a (8.2%, 24/293), 6a (5.1%, 15/293) and 6u (2.4%, 7/293). The distribution of HCV subtypes was mostly related to geographic location. Subtypes 3b, 3a, and 6n were detected in all six prefectures, however, the other four subtypes were detected only in parts of the six prefectures. Phylogeographic analyses indicated that 6n, 1a and 6u originated in the western prefecture (Dehong) and spread eastward and showed genetic relatedness with those detected in Burmese. However, 6a originated in the southeast prefectures (Honghe and Wenshan) bordering Vietnam and was transmitted westward. These subtypes exhibited different evolutionary rates (between 4.35×10⁻⁴ and 2.38×10⁻³ substitutions site^-1 year^-1) and times of most recent common ancestor (tMRCA, between 1790.3 and 1994.6), suggesting that HCV was multiply introduced into Yunnan. Naturally occurring resistance-associated mutations (C316N, A421V, C445F, I482L, V494A, and V499A) to NS5B polymerase inhibitors were detected in direct-acting antivirals (DAAs)-naïve IDUs.

Conclusion

This work reveals the temporal-spatial distribution of HCV subtypes and baseline HCV drug resistance among HIV-infected IDUs in Yunnan. The findings enhance our understanding of the characteristics and evolution of HCV in IDUs and are valuable for developing HCV prevention and management strategies for this population.

Genotypic distribution and hepatic fibrosis among HIV/HCV co-infected individuals in Southern China: a retrospective cross-sectional study

Background

End-stage liver disease and hepatocellular carcinoma due to hepatitis C virus (HCV) co-infection are increasingly common causes of death among HIV-infected individuals. However, there are few clinical investigations of HIV/HCV co-infected individuals from low and middle-income nations. Here, we compare the epidemiology of HCV-infected and HIV/HCV co-infected individuals in Southern China and examine hepatic fibrosis scores in co-infected individuals.

Methods

We conducted a retrospective cross-sectional study of treatment-naïve HIV/HCV co-infected and HCV mono-infected subjects. Bivariate and multivariate models were used to examine the association between demographics and HCV genotype. Among co-infected individuals, we also studied the relationship between fibrosis scores derived from non-invasive studies and HCV genotype.

Results

Data were collected from 175 HCV-infected individuals, including 89 (51 %) HIV/HCV co-infected individuals. HIV/HCV co-infection was correlated with intravenous drug use (AOR 46.25, p < 0.001) and not completing high school (AOR 17.39, p < 0.001) in a multivariate model. HIV/HCV co-infected individuals were more likely to be infected with HCV genotype 6a (p < 0.0001) or 3a (p < 0.023), whereas increased fibrosis (FIB-4 score) was associated with HCV genotype 3a infection (β 2.18, p < 0.001).

Discussion

Our results suggest that intravenous drug use is driving HIV/HCV co-infection in Southern China. While additional studies are needed, HCV genotype 6a is more common and genotype 3a appears to be associated with more severe hepatic fibrosis in co-infected individuals.

Conclusions

Future HIV/HCV co-infection research in China should focus on at risk populations, HCV testing uptake, and genotype-specific treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1135-1) contains supplementary material, which is available to authorized users.

Phylogenetic analysis of HCV subgenotypes in patients from Sichuan province in China based on the NS5B region

The classification of hepatitis C virus (HCV) genotypes is of clinical importance as it may help to predict drug therapy responses and estimate treatment duration. The classical method of HCV subgenotype classification is whole genome sequencing (WGS). However, the high cost and time-consuming nature of WGS limits its usage in clinical practice. A number of studies have been conducted to confirm whether specific regions of HCV could replace WGS in the classification of HCV subgenotypes. In the present study, we used the HCV database to select HCV sequences from different countries. The neighbor-joining method was used to construct phylogenetic trees based on different regions of HCV (core, E1, E2 and NS5B), to confirm which region could replace WGS in subgenotype classification. Our results indicated that the core, E1 and E2 regions could not be used to classify the HCV subgenotype correctly (core failed to recognize subgenotypes c and a, E1 failed to discriminate between subgenotypes a and b, and E2 failed to identify subgenotypes a and c). The NS5B region provided the correct subgenotype classification. The HCV samples (n=153) collected from patients in Sichuan province, (Southwest China) were sequenced and classified based on the NS5B region. The results indicated that the major subgenotype of HCV in patients from Sichuan was 1b (51.6%, n=79); other subgenotypes included 3b (30.1%, n=46), 3a (7.8%, n=12), 6a (8.5%, n=13), 2a (n=2) and 6n (n=1). The data from our analysis may prove to be helpful in future epidemiological investigations of HCV, and may aid in the prevention and clinical treatment of HCV.

Hepatitis C virus genotype and subtype distribution in Chinese chronic hepatitis C patients: nationwide spread of HCV genotypes 3 and 6

Background

Hepatitis C virus (HCV) genotype and subtype are related to disease progression and response to antiviral therapy. Current HCV genotype and subtype distribution data, especially for genotypes 3 and 6, are limited in China. Our purpose was to investigate the current HCV genotype and subtype distributions in chronic hepatitis C patients in China.

Methods

Chronic hepatitis C patients (n = 1012) were enrolled, and demographic information and possible transmission risk factors were collected. Serum samples were subjected to reverse-transcription polymerase chain reaction, followed by direct DNA sequencing and phylogenetic analysis of the NS5B and core/E1 regions to determine HCV genotypes/subtypes. The geographical distributions of HCV genotypes/subtypes were analyzed. Demographic information and transmission risk factors were compared between different HCV genotypes/subtypes.

Results

Four genotypes and seven subtypes of HCV were detected in 970 patients. Subtypes 1b, 2a, 3a, 6a, 3b, 6n, and 1a were detected at frequencies of 71.96 %, 19.90 %, 3.20 %, 2.16 %, 1.96 %, 0.41 %, and 0.41 %, respectively. Genotypes 3 and 6 showed an increasingly wide geographic distribution over time. Patients with subtypes 1b and 2a were older than those with 3a, 3b, 6a, and 6n subtypes (p < 0.05 in all subtypes). More genotype 1 and 2 patients underwent blood transfusion than those with genotype 3 (all p < 0.05). More genotype 3 and 6 patients had a history of intravenous drug use than those with genotypes 1 and 2 (all p < 0.05).

Conclusions

Though subtypes 1b and 2a are still the most prevalent HCV subtypes in China, genotype 3 and 6 HCV infections have already spread nationwide from southern and western China.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-015-0341-1) contains supplementary material, which is available to authorized users.

Sustained Virologic Response to a Dual Peginterferon alfa-2a and Ribavirin in Treating Chronic hepatitis C Infection: A Retrospective Cohort Study

In Myanmar, hepatitis C virus (HCV) infection prevalence is 2%. A combination therapy of pegylated interferon alfa-2a and ribavirin (PEG-IFNa/RBV) is a standard treatment, but the effect of this antiviral therapy needs evaluation as to determine the efficacy and safety of dual PEG-IFNa/RBV therapy in treating patients infected with HCV in Myanmar.This was a retrospective analysis of data from a single clinic exclusively for gastrointestinal diseases in Yangon, Myanmar. We assessed treatment responses at the defined time points and stratified by genotypes of HCV. We also determined incidences of adverse events (AEs). We investigated independent predictors of sustained virologic response (SVR) in the participants.A total of 362 HCV-infected cases were included in this study. The majority were females (51.7%) with mean age of 47.12 years (±11.6) and noncirrhosis patients (82%). Rapid virologic response (RVR), early virologic response (EVR), end of treatment response (ETR), and SVR 24 weeks after completion of the dual treatment were 50.3% (178/362), 88% (314/357), 80.1% (286/357), and 85.6% (167/195), respectively. The most frequently reported AEs were nausea/anorexia (72.8%) and flu-like symptoms (62.4%). In multivariate analysis, 4 factors were independently associated with SVR; SVR to genotype 3 (odds ratio [OR] 2.4, 95% CI: 1.24-4.62), EVR (OR 0.54, 95% CI: 0.3-0.95), and duration of treatment (OR 1.52, 95% CI: 1.18-1.98). Study limitations were acknowledged.The efficacy and safety of the dual therapy in treating HCV-infected patient in Myanmar was acceptable. We recommend a prospective randomized control trial looking at duration of therapy and rates of achieving SVR, which could significantly impact the care of HCV-infected patients in Myanmar and perhaps other countries as well.

Rapid detection of HCV genotyping 1a, 1b, 2a, 3a, 3b and 6a in a single reaction using two-melting temperature codes by a real-time PCR-based assay

The genotype of the hepatitis C virus (HCV) is an important indicator for antiviral therapeutic response. We hereby described development of a rapid HCV genotyping approach that enabled the identification of the six most common HCV subtypes of Asia, i.e., 1a, 1b, 2a, 3a, 3b, and 6a, in a single reaction. Using two dual-labeled, self-quenched probes that target the core region of the HCV genome, the exact subtype could be accurately identified by two-melting temperature codes determined from the two respective probes in a real-time PCR assay. Analytical sensitivity studies using armored RNA samples representing each of the six HCV subtypes showed that 5 copies/reaction of HCV RNA could be detected. The assay was evaluated using 244 HCV-positive serum samples and the results were compared with sequencing analysis. Of the 224 samples, subtype 3a (127, 52.3%) was the dominant, followed by 1b (51, 20.9%), 3b (47, 19.3%), 2a (8, 3.3%), 6a (4, 1.6%) and the least was subtype 1a (1, 0.4%). Moreover, 6 (2.5%) mixed infection samples were also detected. These results were fully concordant with sequencing analysis. We concluded that this real-time PCR-based assay could provide a rapid and reliable tool for routine HCV genotyping in most Asian countries.

Genotypic distribution of hepatitis C virus in Thailand and Southeast Asia

The majority of hepatitis C virus (HCV) infection results in chronic infection, which can lead to liver cirrhosis and hepatocellular carcinoma. Global burden of hepatitis C virus (HCV) is estimated at 150 million individuals, or 3% of the world’s population. The distribution of the seven major genotypes of HCV varies with geographical regions. Since Asia has a high incidence of HCV, we assessed the distribution of HCV genotypes in Thailand and Southeast Asia. From 588 HCV-positive samples obtained throughout Thailand, we characterized the HCV 5’ untranslated region, Core, and NS5B regions by nested PCR. Nucleotide sequences obtained from both the Core and NS5B of these isolates were subjected to phylogenetic analysis, and genotypes were assigned using published reference genotypes. Results were compared to the epidemiological data of HCV genotypes identified within Southeast Asian. Among the HCV subtypes characterized in the Thai samples, subtype 3a was the most predominant (36.4%), followed by 1a (19.9%), 1b (12.6%), 3b (9.7%) and 2a (0.5%). While genotype 1 was prevalent throughout Thailand (27–36%), genotype 3 was more common in the south. Genotype 6 (20.9%) constituted subtype 6f (7.8%), 6n (7.7%), 6i (3.4%), 6j and 6m (0.7% each), 6c (0.3%), 6v and 6xa (0.2% each) and its prevalence was significantly lower in southern Thailand compared to the north and northeast (p = 0.027 and p = 0.030, respectively). Within Southeast Asia, high prevalence of genotype 6 occurred in northern countries such as Myanmar, Laos, and Vietnam, while genotype 3 was prevalent in Thailand and Malaysia. Island nations of Singapore, Indonesia and Philippines demonstrated prevalence of genotype 1. This study further provides regional HCV genotype information that may be useful in fostering sound public health policy and tracking future patterns of HCV spread.