A real-time Taqman method for hepatitis C virus genotyping and methods for further subtyping of isolates

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.

Spontaneous loss of hepatitis C virus RNA from serum is associated with genotype 1 and younger age at exposure

A variety of factors have been associated with spontaneous loss of hepatitis C virus (HCV)-RNA from serum, including infecting HCV type, although results are conflicting. This study aimed to investigate further whether infecting HCV type was linked to spontaneous loss of HCV-RNA. Serum samples from 321 untreated HCV antibody positive patients presenting at the Hepatology clinic at Addenbrooke's Hospital, Cambridge between 2004 and 2007 were tested. These individuals were classified either as HCV antibody and HCV-RNA positive (viremic, n = 219) or HCV antibody positive and repeatedly HCV-RNA negative (non-viremic, n = 102). Infecting HCV type was identified by genotyping (viremic) or serotyping (non-viremic). Binomial regression analysis investigated the independent effect of HCV type on spontaneous loss of HCV-RNA from serum by comparing the two groups. Ninety-one percent of patients were found to be either genotype 1 or genotype 3. The prevalence of type 1 infection was greater among non-viremic (64.5%) than viremic individuals (45%). After controlling for the effects of potential confounding factors, multivariable analyses showed that individuals with type 1 infections were more likely to be non-viremic than genotype 3 infections (RR = 2.07; 95% CI: 1.25, 3.43; P = 0.005). Individuals infected at an older age were also less likely to become HCV-RNA negative spontaneously (RR = 0.42 comparing those infected at ≥20 years of age against those infected at <20 years of age, 95% CI: 0.25, 0.72; P = 0.002). In conclusion, the results suggest that HCV genotype 1 infections are more likely than genotype 3 infections to become spontaneously non-viremic, as are infections acquired at younger age.