Prevalence of antibody to hepatitis C virus in HBsAg-negative chronic liver disease in Hong Kong using different assays

Viral hepatitis C in Hong Kong

OBJECTIVE

Hepatitis C virus (HCV) infection can lead to serious liver disease. Its medico-socio-economic burden on society can be immense. This study investigates the epidemiology of HCV infection in Hong Kong.

METHODS

Data from the Department of Health, relevant publications from Medline search and data from two acute hospitals were reviewed.

RESULTS

The prevalence of anti-HCV among voluntary blood donors is stable, remaining at approximately 0.035-0.099% over the past 10 years, and is higher in the older age group. Among the high-risk groups, the anti-HCV prevalence is as follows: (1) hospital patients 0.8%, (2) intravenous drug users 46.0%, (3) patients infected with HIV 7.9%, (4) children with transfusion-dependent hematologic disease 16.3%, (5) patients on continuous ambulatory peritoneal dialysis 1.8%, patients on hemodialysis 16.4%, recipients of kidney transplants 6.2% and (6) patients with hepatocellular carcinoma 7.3%. Among blood donors, 58.8% were infected with HCV genotype 1b and 27.0% with genotype 6a. Genotype 6a is particularly common among intravenous drug users.

CONCLUSION

Hong Kong has a low prevalence of HCV infection. Patients are mostly infected through transfusion with blood or products prior to the introduction of anti-HCV screening to the blood transfusion service. Illicit drug use constitutes another significant risk. Since 1997, there has been a great increase in population movement between China and Hong Kong which might affect the epidemiology of HCV infection.

Evaluation of five hepatitis C virus screening tests and two supplemental assays: performance when testing sera from sexually transmitted diseases clinic attendees in the USA

The performances of five screening tests (recombinant peptide-based first and second generation tests from Abbott and Ortho, and a synthetic peptide-based test from Biochem Immunosystems) and two supplemental tests: recombinant peptide- based, Abbott neutralization test and Chiron second generation recombinant immunoblot assay (RIBA 2), were evaluated for their ability to detect hepatitis C virus (HCV) antibodies in a population of 276 individuals attending a sexually transmitted diseases (STD) clinic in the USA. Although the five screening tests produced a variable number (35-62) of repeatedly reactive samples, only 13% (36/276) were classified as true positives by the supplemental tests. Thirty-four of the 36 were reactive by all screening tests and 32 of the true positives were reactive by both supplemental tests, while 2 did not neutralize but were reactive in the RIBA 2 test. Of the remaining 2 of the true positives which were discordant by several of the screening assays, 1 was confirmed by both supplemental assays but the other required a chemiluminescent enhancement technique to show positivity in RIBA 2. The sensitivities of the first and second generation Abbott and Ortho tests ranged from 97% to 100% and that of the Biochem test was 94%. The specificities of these tests ranged from 89.2% to 99.6%. The second generation Ortho test presented 9.4% (26/276) false positives. The use of second generation Ortho as a screening test would lead to an excessive number of confirmatory false positives. the positive predictive values of the screening tests ranged from 58.1% to 97.1%. Although the synthetic peptide based Biochem test exhibited the best overall indices, the presence of 2 false negative results would prevent its use as a singular screening test. Nevertheless its high specificity may lend itself to be used as a second screening test before confirmatory testing with RIBA 2.

Lack of association between hepatotropic transfusion transmitted virus infection and oral lichen planus in British and Italian populations

BACKGROUND

A possible association between oral lichen planus (OLP) and chronic hepatic disease has been found in some populations, although this is probably geographically influenced. In 1997 a new hepatotropic virus, transfusion transmitted virus (TTV), was identified but has not been studied in relation to OLP.

OBJECTIVE

The present investigation evaluated the genoprevalence of TTV DNA in the sera of British and Italian patients suffering from OLP using two different sets of primers to identify TTV subgenomic DNA.

METHODS

Study groups comprised 40 adult subjects (21 British, 19 Italian) with OLP. For each country, two control groups, a disease-control group and a healthy-control group, were included. The presence of TTV DNA in the sera of patients and control subjects was assessed using two different polymerase chain reactions (PCR) and DNA sequence analysis.

RESULTS

Statistical analysis did not reveal evidence of any association between TTV infection and OLP or country of residence.

CONCLUSION

An association between TTV and OLP is unlikely.

Prevalence of hepatitis C antibody in patients with chronic liver disease and hepatocellular carcinoma in Korea

To investigate the contribution of hepatitis C virus (HCV) to chronic liver disease and hepatocellular carcinoma (HCC) in Korea, antibodies to HCV (anti-HCV) were tested by enzyme immunoassay in 1759 patients with chronic liver disease and HCC, and in 808 healthy adults. The prevalence of anti-HCV was 1.6% in 808 controls. Anti-HCV was present in 32 (7.7%) of 418 hepatitis B surface antigen (HBsAg)-positive and 128 (53.1%) of 241 HBsAg-negative patients with chronic hepatitis, 16 (6.0%) of 265 HBsAg-positive and 90 (30.5%) of 295 HBsAg-negative patients with liver cirrhosis, and 16 (4.8%) of 330 HBsAg-positive and 61 (29.0%) of 210 HBsAg-negative patients with HCC. Antibodies to hepatitis B core antigen (anti-HBc) were present in 80-88% of patients who were seropositive for anti-HCV and seronegative for HBsAg. Among the sera from 114 patients with HBsAg-negative and anti-HCV-positive chronic liver diseases, HBV DNA and HCV RNA were detected by polymerase chain reaction (PCR) in 54 (47.4%) and 61 (53.3%), respectively. Both HBV DNA and HCV RNA were detected in 4 (4.4%) samples. The mean age of the patients with both HBsAg and anti-HCV was not different from that of patients who were seropositive for HBsAg alone. These findings indicate that current and/or past HBV infection is still the main cause of chronic liver disease in Korea.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of hepatitis B and C viruses in healthy Indonesian blood donors

Blood samples were collected from 7572 healthy volunteer blood donors from 21 of the 27 Indonesian provinces, and tested for antibodies to hepatitis C virus (anti-HCV) using the new second-generation enzyme immunosorbent assay, and also tested for hepatitis B surface antigen (HBsAg). We detected anti-HCV in 2.1% of the blood donors. No statistically significant difference was found between males and females or between locations, but there was a statistically significant increasing likelihood of anti-HCV prevalence with increasing age. HBsAg was found in 8.8% of the 3839 tested donors. There was no statistically significant difference between sexes or age groups, but there was a statistically significant higher prevalence in the islands of Sulawesi and eastern Indonesia. Only 7 individuals, from 5 locations, were both anti-HCV and HBsAg positive. Based on responses to a questionnaire, a history of surgery, blood transfusion, intravenous medication, and acupuncture were identified as risk factors for the presence of anti-HCV. No such risk factor was identified for HBsAg prevalence. The combined data suggest separate modes of transmission for the 2 viruses, and indicate the need for continued surveillance for these agents in Indonesian blood banks.

Chronic liver disease in Peru: role of viral hepatitis

The prevalence of antibodies to hepatitis C virus (anti-HCV) was determined in 105 patients with biopsy-proven chronic liver disease and 128 comparison patients without any evidence of liver pathology living in Lima, Peru. Using a second-generation EIA screening and supplemental immunoblot assay, anti-HCV was detected in four of 13 patients with chronic hepatitis, in 11% of 85 patients with cirrhosis, and in none of seven patients with hepatocellular carcinoma. Only two (1.6%) comparison patients without liver disease had anti-HCV. Hepatitis B surface antigen (HBsAg) was found in 23% of patients with chronic hepatitis, 12% of patients with cirrhosis, and three of seven patients with hepatocellular carcinoma. There was no evidence of chronic viral hepatitis or alcohol abuse (reported by one-third of subjects) in 48% of chronic liver disease patients. These preliminary data suggest that among this South American population neither hepatitis B nor hepatitis C infection is the predominate cause of chronic liver disease and that other infectious or environmental factors may be important.

Laboratory diagnosis of human hepatitis viruses

Conventional serologic methods of antigen or antibody detection are now widely applied for diagnosis of hepatitis viruses A, B, C, and D. Nucleic acid quantitation has become very useful for monitoring response to antiviral therapy in cases of hepatitis B and C. Special confirmatory testing of HCV serologies can be quite specific, but overall serologies for HCV lack sensitivity for early diagnosis. Thus HCV RNA detection may ultimately be the preferred method for HCV diagnosis and for screening blood donors. Unfortunately, HEV diagnosis may rest on the efforts of research laboratories for electron microscopy, Western blot, or nucleic acid detection.

Low prevalence of hepatitis C virus antibodies in chronic liver disease in northwest China

To evaluate the prevalence of hepatitis C virus infection in northwest China, 179 chronic liver disease patients in this area were examined for antibody to hepatitis C virus core protein (anti-HCVcore). This antibody was found in only 5 (14 percent) of 37 chronic non-A, non-B liver disease patients, in 11 (16%) of 67 asymptomatic hepatitis B virus carriers, and in 20 (27%) of 75 chronic hepatitis B patients. High titers of anti-HCVcore (cut off index > 2) were observed in 3 (60%), 5 (45%), and 9 (45%) of the anti-HCVcore-positive cases of these groups, respectively. We further investigated the seroprevalence of antibodies to hepatitis B virus in the 37 chronic non-A, non-B liver disease patients. All 5 anti-HCVcore-positive cases were positive for a hepatitis B virus marker, with only 44% (14/32) of the anti-HCVcore-negative patients (P < 0.05). Based on these findings, it is concluded that the prevalence of hepatitis C virus infection in chronic non-A, non-B liver disease is unexpectedly low in northwest China and that hepatitis B and C viruses seem to have a similar mode of infection in that area.