Distribution of HCV genotypes in patients infected by different sources

Do differences exist between chronic hepatitis C genotypes 2 and 3?

INTRODUCTION

Six genotypes of the hepatitis C virus (HCV) have been identified thus far, and their distribution is well defined. Genotype 1, which is the most prevalent worldwide, is always compared to genotypes 2 and 3, particularly in terms of treatment response. However, little is known about the differences between genotypes 2 and 3 because these genotypes are analyzed together in most studies. Therefore, the aim of this study was to evaluate differences in the clinical, epidemiological, laboratory, and histological parameters between HCV-2 and HCV-3.

METHODS

Patients with chronic hepatitis C infected with genotypes 2 and 3 were studied retrospectively and compared according to clinical, laboratory, and histological aspects. Hepatitis C virus-ribonucleic acid (HCV-RNA) was analyzed quantitatively by TaqMan® real-time PCR, and the HCV genotype was determined by sequencing the 5'-untranslated region.

RESULTS

A total of 306 patients with chronic HCV-2 (n=50) and HCV-3 (n = 256) were studied. Subtype 2b (n=17/50) and subtype 3a (n=244/256) were the most prevalent among patients infected with HCV-2 and HCV-3, respectively. The mean age was 47 ± 10 years, and there was a predominance of men in the group studied (61%). Comparative analysis between HCV-2 and HCV-3 showed a younger age (p=0.002), less prevalence of arterial hypertension (p=0.03), higher serum albumin levels (p=0.01), more advanced stage of liver fibrosis (p=0.03), and higher frequency of steatosis in patients with HCV-3 (p=0.001). After multivariate regression analysis, all the variables, except serum albumin, remained as variables associated with HCV-3 in the final model.

CONCLUSIONS

Clinical and histological differences exist between HCV-2 and HVC-3, which suggests the need for separate analyses of these genotypes.

New perspectives in occult hepatitis C virus infection

Occult hepatitis C virus (HCV) infection, defined as the presence of HCV RNA in liver and in peripheral blood mononuclear cells (PBMCs) in the absence of detectable viral RNA in serum by standard assays, can be found in anti-HCV positive patients with normal serum levels of liver enzymes and in anti-HCV negative patients with persistently elevated liver enzymes of unknown etiology. Occult HCV infection is distributed worldwide and all HCV genotypes seem to be involved in this infection. Occult hepatitis C has been found not only in anti-HCV positive subjects with normal values of liver enzymes or in chronic hepatitis of unknown origin but also in several groups at risk for HCV infection such as hemodialysis patients or family members of patients with occult HCV. This occult infection has been reported also in healthy populations without evidence of liver disease. Occult HCV infection seems to be less aggressive than chronic hepatitis C although patients affected by occult HCV may develop liver cirrhosis and even hepatocellular carcinoma. Thus, anti-HCV negative patients with occult HCV may benefit from antiviral therapy with pegylated-interferon plus ribavirin. The persistence of very low levels of HCV RNA in serum and in PBMCs, along with the maintenance of specific T-cell responses against HCV-antigens observed during a long-term follow-up of patients with occult hepatitis C, indicate that occult HCV is a persistent infection that is not spontaneously eradicated. This is an updated report on diagnosis, epidemiology and clinical implications of occult HCV with special emphasis on anti-HCV negative cases.

Diversity of hepatitis C virus genotypes among intravenous heroin users in Taiwan

INTRODUCTION

Limited information is available about genotypes of hepatitis C virus (HCV) in intravenous heroin users in Taiwan. The purpose of this study was to examine the concordance of the detection of antibody to HCV and HCV-RNA and to determine the distribution of HCV genotypes in male intravenous heroin users.

METHODS

This was a cross-sectional study. The study population included 274 intravenous heroin drug users newly sentenced in a male prison in central Taiwan from November 2004 to February 2005, whose antibodies to HCV were positive, and antibodies to human immunodeficiency virus were negative. The mean age was 33.9 years (standard deviation, 7.8). The molecular diagnosis used to identify HCV-RNA was PCR.

RESULTS

Among 274 subjects, 214 subjects were found to contain HCV-RNA. Positive predictive value of HCV infection using antibody to HCV as an indicator was 78.1%. Among 214 subjects, HCV genotype 2a was the most predominant (58.9%, n = 126), followed by 1a (17.3%, n = 37), 1b (14.5%, n = 31), 2b (8.9%, n = 19) and 1a + 2b (0.4%, n = 1). Age-specific analysis also showed genotype 2a was the most prominent genotype among the 4 age groups, with the highest prevalence in groups aged 20 to 29 years and 30 to 39 years (53.3% and 67.6%, respectively).

CONCLUSIONS

The concordance of antibody to HCV and HCV-RNA is remarkable in selected high-risk groups. HCV genotype 2a is the most prevalent in male intravenous heroin users in central Taiwan, especially in aged 20 to 29 years and aged 30 to 39 years.

Prevalence of hepatitis C in a drug using and non-using welfare population

CONTEXT

Drug use is a primary route for the transmission of the Hepatitis C virus (HCV). A substantial proportion of welfare recipients have been shown to be substance abusers. In addition, federal legislation has imposed limits on the number of months individuals may receive benefits and has mandated most recipients to participate in a 'work activity' in exchange for benefits. HCV symptoms may inhibit welfare recipients' ability to seek and maintain employment.

OBJECTIVE

To assess the prevalence of HCV in a sample of Temporary Assistance to Needy Families (TANF) recipients and the effects of HCV antibody seropositivity on employability.

DESIGN, SETTING, AND PARTICIPANTS

The sample for this study consisted of 380 individuals participating in a longitudinal study of employment patterns among TANF recipients in Houston, TX, funded by the National Institute on Drug Abuse (NIDA). Private interviews regarding welfare receipt, employment, and drug use were conducted at intake into the study and at 4-month intervals for one year. Participants agreed to a one-time blood test. Blood samples were tested for the presence of HCV antibodies by enzyme linked immunoassay.

MAIN OUTCOME MEASURE

Employment status over time by HCV antibody status.

RESULTS

Overall, 12% of all participants tested positive for the presence of HCV antibodies. A significantly greater proportion of chronic drug users (31%) than non-drug users (4%) tested positive for the presence of Hepatitis C antibodies. Those who tested positive for hepatitis C had significantly lower rates of employment.

CONCLUSIONS

Potential infection with Hepatitis C may constitute an employment barrier for many welfare recipients.

Distribution of HCV genotypes among risk groups in Serbia

Blood samples from 190 patients that were anti-hepatitis C virus (HCV) positive were genotyped and 165 were found to contain HCV-RNA. Genotyping was performed by PCR based on type-specific primers (117 isolates) and LiPA test (48 isolates) and verifying by sequencing. In Serbia, the most frequent genotype was 1b (49.1%), followed by genotype 3 (21.2%) and genotype 1a (8.5%). The frequency of genotypes 2 and 4 was below 5% and mixed infections were encountered in 9.1% of cases. Distribution of genotypes was monitored in different risk groups: intravenous drug abusers, patients under blood transfusion, patients with previous history of surgery, patients undergoing hemodialysis and those with unknown risk factors. Genotype distribution is essentially the same in all the groups, except for the patients undergoing hemodialysis and those with previous history of surgery where significant difference exists compared with the group with unknown route of transmission (p < 0.001 and p < 0.05, respectively). There exists significant age-dependent genotype 3 distribution in Serbian population (p < 0.01).

Haemophilic patients with hepatitis C have higher viral load compared to other well-defined patient groups

Comparison of hepatitis C viral load between different patient populations has been hampered by the use of different technology in individual studies. We had the impression that haemophilic (HAEM) patients had a higher serum load of hepatitis C virus (HCV) compared to other HCV-infected patients. We therefore studied viral load and genotypes in active illicit drug users (IDU), HAEM patients and patients with post-transfusion hepatitis (PTH). The study comprises 225 HCV-RNA positive patients, 117 IDU, 60 HAEM patients and 48 PTH patients. All patients were anti-HIV negative. HCV-RNA was measured with a quantitative reverse transcription polymerase chain reaction (RT-PCR) method, HCV-genotypes were determined with genotype specific primers in RT-PCR in 221 patients. Four patients could not be genotyped with our assay and were excluded. Overall viral load was higher in genotypes 1 and 2 compared to genotype 3, median values of HCV-RNA were 1,400 x 10(3) geq ml(-1), 2,700 x 10(3) geq ml(-1) and 270 x 10(3) geq ml(-1), respectively. HAEM patients had significantly higher viral load for both genotypes 1 and 3 compared to the IDU and PTH patients. In a multiple linear regression model HCV-RNA viral load was independently associated with HAEM and genotype, but not to age, gender or disease duration. In conclusion, HAEM patients have higher viral load than IDU and PTH patients. The reason for this is unknown, but it may be due to host factors or mode of transmission with multiple inoculations.

Detection of HGV in serum and peripheral blood mononuclear cells of maintenance haemodialysis patients

The aim of the present study was to investigate the prevalence of hepatitis G virus (HGV) and also hepatitis C virus (HCV) infections in maintenance haemodialysis patients, and to identify extrahepatic sites as HGV reservoirs. HGV RNA was detected in the serum of 6/61 (10%) patients and in the peripheral blood mononuclear cells of 2/61 (3%) patients (one of whom was serum negative). These findings suggest that lymphoid cells constitute an extrahepatic HGV reservoir. HCV RNA was detected in 7/61 (11%) patients. Five of these patients (71%) were identified as carrying HCV genotype 1b. Co-infection with HCV and HGV was detected only in one patient. Haemodialysis patients are at risk for HGV infection, by nosocomial routes or via transfusions. HGV itself does not seem to be an important cause of hepatitis since all six HGV RNA positive patients not co-infected by HCV or HBV showed normal ALT values.

The most prevalent hepatitis C virus genotypes in England and Wales are 3a and 1a

Hepatitis C virus (HCV) genotypes were assigned to 567 individuals by restriction fragment length polymorphism analysis of the 5' noncoding region of the HCV genome following reverse transcription-polymerase chain reaction. The groups of individuals in this study included hemophilia patients, injecting drug users (IDUs), blood donors, antenatal patients, those attending genitourinary medicine (GUM) clinics, and patients with chronic liver disease, all from England and Wales. The majority of HCV infections were types 1a (32%), 1b (15%), or 3a (37%). The genotype distribution in individual groups was similar to the overall genotype distribution except for hemophilia patients, in whom the frequencies were 1a (39%), 1b (23%), and 3a (21%). With the exception of hemophilia patients, subpopulations in England and Wales appear to share common modes of HCV transmission. There is a need for continued surveillance to monitor the spread of possibly more virulent or drug-resistant HCV genotypes.