Positive anti-HCV Results Research Articles

Diagnosis of hepatitis C virus infection in pregnant women in the healthcare system in Poland

The hepatitis C virus (HCV) is globally recognized as a serious public health concern. Current statistics indicate that approximately 2% of people worldwide and 1.9% of people in Poland suffer from HCV infection.This study was conducted to assess the anti-HCV seroprevalence in pregnant women in Poland and subsequently provide recommendations on the rationale for obligatory screening.A total of 42,274 women participated in our study, of which 16,130 were pregnant. We were granted access to their health data stored in the form of electronic medical records kept by the network of outpatient clinics throughout Poland.The lowest rate of positive anti-HCV test results was found in women ages 25 to 34 (0.73%); however, younger and older age groups had similar rates (15–24 = 0.86%; 35–44 = 0.84%). Additional analysis of data from the period between 2011 and 2014 revealed a downward trend in the proportion of positive anti-HCV tests among pregnant women (mean positive anti-HCV = −0.001 × year + 1.9451; R2 = 0.7274). Regardless of the gradual increase in the number of female patients undergoing screening between 2004 and 2015, there has been a constant decrease in the rate of positive cases. The rate of pregnant women potentially infected with HCV was twice as lower than that in a control group of women undergoing tests for other medical circumstances: 0.76% vs 1.67% (P < 0.0001).Analysis of real-world data of female patients in Poland provides evidence that screening based on an individual's medical history and behavioral risk factors in clinical circumstances would be more effective than obligatory testing of all pregnant women.

Thrombocytopenia as a Clinical Manifestation of Hepatitis C Among Patients With a Positive Anti-HCV Test

Background: The hepatitis C virus (HCV) has been recognized as the cause of thrombocytopenia (defined as a platelet count of < 150,000 platelets/uL) occurring in patients with chronic hepatitisC. Thrombocytopenia occurs in 64% - 76% of patients with cirrhosis and/or fibrosis, compared with 6% of non-cirrhotic patients with chronic liver disease. Objectives: The aim was to study the prevalence of thrombocytopenia in HCV patients without cirrhosis and splenomegaly. Patients and Methods: A cross-sectional study was carried out in the gastrointestinal out patient department (G.I. OPD) of the Sindh institute of urology and transplantation (SIUT) from September-November 2013. 30 patients aged between 18 - 60 years with a positive anti-HCV result were included. Patients with enlarged spleen, liver cirrhosis on an ultrasound of the abdomen, and throm- bocytopenia related to other causes were excluded from the study. Results: A total of 30 patients satisfying the inclusion criteria were selected for study. The mean age of the patients was 42.2 11.4 (16 - 60), and they included 21 females and 7 males. The majority of patients had normal liver function tests with normal spleen size. On the CBC, 13 had platelets of less than 150,000/ L and 17 patients had a platelet count in the normal range, i.e., 150,000 - 400,000/ L. The prevalence of thrombocytopenia was found to be 43.3% among those with hepatitis C. Conclusions: The conducted study showed moderate frequency of hepatitis C-induced thrombocytopenia in patients without hep- atic fibrosis and splenomegaly among the Pakistani population.

Inadequate seroprotection against hepatitis B virus and one detected case of hepatitis C virus infection among patients with inflammatory bowel disease.

The prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among patients with inflammatory bowel disease (IBD) from central and eastern European countries is unknown. Postvaccination HBV immunity in an immunocompromised host may wane. The aims of the study were as follows: to assess the immune status for HBV and HCV among IBD patients, the level of HBV seroprotection, and to compare the immune status of patients who received mandatory versus recommended HBV vaccination. Serological markers of HBV and HCV (anti-HBs, anti-HBc, HBsAg, and anti-HCV) were determined in 147 consecutive IBD patients. An anti-HBs of 10 IU/l or more was considered as immunity to HBV infection. HBV infection was detected in 21 patients, whereas 11 of them recalled previous HBV vaccination. Sixty-eight noninfected patients had a level of anti-HBs 10 IU/l or more and only 29% reached the cut-off level of 100 IU/l. Among patients vaccinated obligatorily, two patients had previous HBV infection and 15% did not have an adequate seroprotection against HBV. Patients who received a mandatory HBV vaccine more frequently had a protective anti-HBs level than those vaccinated voluntarily (P<0.001). One positive anti-HCV result was found. A mandatory HBV vaccination significantly increased the number of patients effectively protected against HBV; however, a remarkable number of vaccinated IBD patients had inadequate HBV seroprotection. All IBD patients should be screened for HBV and HCV infections and monitored for anti-HBs titers.

HBsAg and anti-HCV screening in elderly hospitalized patients of a German tertiary referral centre.

Elderly patients are under-represented in hepatitis B and C screening approaches, but may be at increased risk for advanced liver disease. We therefore screened a hospitalized elderly population. 6011 admissions to the department of internal medicine and neurology within one year were screened for HBsAg and anti-HCV (Elecsys(®)-HBsAg and -anti-HCV). Positive anti-HCV results were confirmed with the INNO-LIA™ assay. HCV-RNA was analyzed by real-time PCR in the case of confirmed positive anti-HCV results, HBV-DNA in the confirmed HBsAg positive individuals. Patient´s mean age (62.4 years) was 19 years above that of the average German population. The confirmed HBsAg prevalence was 0.6 %. 34 % (n = 12/35) of HBsAg positive cases were newly diagnosed, three of them presented with HBV-DNA levels > 2000 IU/mL. The confirmed anti-HCV prevalence was 0.9 %. 14 % (n = 8/56) of anti-HCV positive patients were previously undiagnosed. HCV-RNA was positive in three of them. In newly diagnosed individuals cirrhosis was present in 1/12 of the HBsAg and in 3/8 of the anti-HCV positive individuals. Compared to non-infected controls, the following risk factors were significantly more frequent in infected patients: (i) HBsAg: sexual exposure (20 % vs. 2 %), blood transfusion before 1992 (13 % vs. 6 %), referrals from nursing homes (10 % vs. 1 %). (ii) Anti-HCV: blood transfusion before 1992 (41 % vs. 6 %), IVDU (25 % vs. 0.5 %), organ transplantation (20 % vs. 5 %), hemodialysis (11 % vs. 3 %). HBsAg and anti-HCV were underdiagnosed in a senescent population, however, only few cases presented with advanced liver disease. Referrals from nursing homes were at increased risk for HBV infection.

Performance study of the automated immunoassay test anti-hepatitis C virus VIDAS® for the qualitative detection of antibodies anti-hepatitis C virus

Background and aims: Hepatitis C virus (HCV) represents a major worldwide public health problem requiring global action for the diagnosis, treatment and prevention of this infection. HCV is the leading cause of chronic liver disease, including chronic hepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma and it is responsible for about 350,000 deaths yearly. Anti-HCV assays remain the first choice for screening HCV infection in most clinical laboratories. The anti-HCV VIDAS® (bioMérieux, Marcy L’Etoile, France) test has been recently launched and we aimed to evaluate its performance compared with other widely used methods. &lt;br /&gt;Materials and methods: Routine anti-HCV screening of clinical samples was carried out on the ARCHITECT® i2000SR platform (Abbot Laboratories, Abbott Park, IL, USA); out of 8876 samples tested from October 2012 to May 2013, 70 sera with low positive anti-HCV results (1≤S/CO&amp;lt;8) were collected. These samples were tested for the presence of anti-HCV antibodies using anti-HCV VIDAS® and INNO-LIATM HCV score assays (Innogenetics NV, Ghent, Belgium). &lt;br /&gt;Results and conclusions: Positive anti-HCV results were obtained in 61.4% and 41.4% of sera tested with VIDAS® and INNO-LIATM, respectively. Concordance between methods was 63.2% for ARCHITECT® and VIDAS®, 42.6% for ARCHITECT® and INNO-LIATM, and 79.4% for VIDAS® and INNO-LIATM. Anti-HCV VIDAS® demonstrated superior specificity compared to the anti-HCV test ARCHITECT®; therefore, this assay has been introduced in our routine analysis as a second level screening test to select samples to be subjected to confirmatory anti- HCV immunoblot.

Performance evaluation and comparison of the newly developed Elecsys anti-HCV II assay with other widely used assays

BackgroundAnti-HCV assays remain the first choice for screening HCV infection in most clinical laboratories. The Elecsys anti-HCV II assay has been recently launched and we aimed to evaluate its performance compared with other widely used methods. MethodsFour seroconversion panels, 861 consecutive sera under routine clinical conditions, 100 preselected sera with low positive anti-HCV results and 178 samples from patients infected with HIV were tested using Elecsys anti-HCV II, Architect anti-HCV and Vitros anti-HCV assays. Confirmatory testing was performed using RIBA and HCV RNA tests. Moreover, 203 samples with different HCV genotypes were assessed using Elecsys anti-HCV II. ResultsElecsys anti-HCV II detected seroconversion 7–14days earlier than the Architect and Vitros assays. Furthermore, it had 100% sensitivity and superior specificity in screening routine clinical samples, including those with low positive anti-HCV, and detected 97.6% (122/125) anti-HCV-positive samples from HIV-infected patients with HCV viremia. However, the anti-HCV levels in the genotype 3b samples were slightly underestimated. ConclusionsElecsys anti-HCV II shortens the seroconversion window. It is suitable for screening HCV infection in clinical samples, including those from immunocompromised patients, due to the excellent sensitivity and specificity. Further investigation of the subtype inclusivity in a larger sample number might be warranted.

Acute hepatitis C virus infection in a nurse trainee following a needlestick injury

Hepatitis C virus (HCV) infection after biological accident (needlestick injury) is a rare event. This report describes the first case of acute HCV infection after a needlestick injury in a female nursing student at Padua University Hospital. The student nurse was injured on the second finger of the right hand when recapping a 23-gauge needle after taking a blood sample. The patient who was the source was a 72-year-old female with weakly positive anti-HCV test results. Three months after the injury, at the second step of follow-up, a relevant increase in transaminases with a low viral replication activity (350 IU/mL) was observed in the student, indicating HCV infection. The patient tested positive for the same genotype (1b) of HCV as the injured student. A rapid decline in transaminases, which was not accompanied by viral clearance, and persistently positive HCV-RNA was described 1 mo later. Six months after testing positive for HCV, the student was treated with pegylated interferon plus ribavirin for 24 wk. A rapid virological response was observed after 4 wk of treatment, and a sustained virological response (SVR) was evident 6 mo after therapy withdrawal, confirming that the patient was definitively cured. Despite the favourable IL28B gene (rs12979860) CC- polymorphism observed in the patient, which is usually predictive of a spontaneous clearance and SVR, spontaneous viral clearance did not take place; however, infection with this genotype was promising for a sustained virological response after therapy.

The incidence of hepatitis C in patients with thalassemia after screening in blood transfusion centers: a fourteen‐year study

Blood safety is important in all transfusion centers. The aim has always been to try to guarantee the recipient's safety through careful screening and examination of donors' blood samples. In Iran the hepatitis C virus (HCV) screening test became mandatory for blood donations from 1996. We decided to determine the incidence of new cases of HCV in patients with thalassemia, after screening of blood bags was initiated. The study was done on patients with complete files for anti-HCV test results. Only cases that had a confirmed positive anti-HCV result after a negative result were considered as new cases. The incidence rate was estimated and expressed in person-years (PY). Also, for increased accuracy and comparison of incidence in recent years, the incidence rate was calculated at two 7-year intervals (1996-2002 and 2003-2009). A total of 395 files were studied with a mean age of 27.5 years (SD ± 7.99 years). We had 109 (27.5%) anti-HCV positive, of which 21 (19.2% of positive cases) were exposed after 1996 and considered as new cases. The incidence of HCV cases in 14 years (1996-2009) was 4.2/1000 PY. The incidence in the first 7-year period (1996-2002) was 6.2/1000 PY and 1.3/1000 PY in the second 7-year period (2003-2009). The incidence of HCV is on the decline in Iran, both in blood donors and in recipients. We owe this to the improved blood safety in our transfusion center that has taken up better strategies. Even though the residual risk will never reach zero and we may still have new cases of HCV, it will definitely be with a lower rate. The fact that we have had no new cases among our patients with thalassemia since 2005 bears witness to this matter.

Viral Hepatitis Among Somali Immigrants in Minnesota: Association of Hepatitis C With Hepatocellular Carcinoma

Objective To study the frequencies of chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, and their associations with hepatocellular carcinoma (HCC) in immigrant Somalis seen at Mayo Clinic in Rochester, Minnesota. Patients and Methods We determined the frequencies of HBV and HCV infection and HCC in immigrant Somalis seen at Mayo Clinic from July 1, 1996, through October 31, 2009. Non-Somali Olmsted County residents served as controls. Results For Somali males and females, age-adjusted proportions (per 1000 population) were 209 and 123 for hepatitis B surface antigen (HBsAg), 644 and 541 for hepatitis B core antibody (HBcAb), and 99 and 66 for anti-HCV. The comparative proportions in non-Somalis were 20 and 9 for HBsAg, 126 and 97 for HBcAb, and 32 and 17 for anti-HCV. Hepatitis C virus RNA confirmed that 68 of 73 Somalis (93.2%) and 261 of 282 non-Somalis (92.6%) with positive anti-HCV test results had active HCV infection. Of 30 Somali patients with HCC, 22 (73.3%) tested anti-HCV positive (odds ratio [OR], 31.3; 95% confidence interval [CI], 13.0-75.5; P<.001; compared with anti-HCV–negative Somalis), 5 (16.7%) were HBsAg positive (OR, 1.4; 95% CI, 0.5-3.7; P=.53), and 18 (60.0%) were HBcAb positive (OR, 1.8; 95% CI, 0.8-4.2; P=.16). Viral hepatitis was diagnosed coincident with HCC in 9 of 20 patients (45.0%) with HCV-associated HCCs. Only 4 of 24 cases of HCC (16.7%) were detected during surveillance. Conclusion Both HBV and HCV occurred frequently in this sample of Somali immigrants. However, HCV was the major risk factor for HCC. Screening Somali immigrants for HCV infection may enhance the prevention, early detection, and optimal treatment of HCC.

Overestimation of HCV Prevalence by Assessing Positive Anti-HCV Results Only

Overestimation of HCV Prevalence by Assessing Positive Anti-HCV Results Only

Lot-to-lot variation in anti-hepatitis C signal-to-cutoff ratio.

Hepatitis C virus (HCV), the most common chronic viral infection in North America, affects an estimated 2.7 million individuals in the US (1). Hepatitis C is more common in certain populations, including injection drug users, prison inmates, the homeless, dialysis patients, and those seeking care in Veterans Affairs medical centers (2)(3)(4)(5). Hepatitis C is the leading cause for end-stage liver complications, including hepatocellular carcinoma and need for liver transplantation; the frequency of these is expected to increase two- to threefold by 2030 (6). Antibodies to HCV (anti-HCV) can indicate one of three possible conditions: current active infection with HCV, past infection with HCV, or a false-positive reaction (7). Although tests are usually interpreted as positive or negative, samples with low-positive anti-HCV results are usually falsely positive, whereas >90% of samples that are high-positive are from patients who test positive for HCV RNA (8)(9). Recently, the CDC revised guidelines for laboratories, recommending confirmatory testing for samples with low signal-to-cutoff (S/C) ratios (10). When enzyme immunoassays (EIAs) are used, they suggested a S/C ratio <3.8 to identify low-positive samples; when chemiluminescence assays (CAs) are used, a S/C ratio <8.0 was recommended (10). No data exist on the reproducibility of S/C ratios between lots. Because calibration of both EIA and CA methods involves a single point (the cutoff value), S/C ratios may vary significantly between lots. I retrospectively reviewed data for S/C ratios and confirmatory test results by lot of reagent for both EIAs and CAs. The Pathology and Laboratory Medicine Service maintains a blinded database of all patients with positive anti-HCV results; details of the screening program and the assays used have been reported previously (8)(9). A total of 13 714 individuals were tested over a 13-month period by a …

Hepatitis C virus infection in institutionalized psychiatric patients: possible role of transmission by razor sharing.

The objective of this study was to determine if HCV can be transmitted from patient to patient in psychiatric institutions and to determine possible routes of infection. We did a cross-sectional survey of 196 Japanese psychiatric patients tested for HCV and HBV markers and 400 age- and sex-matched controls. Anti-HCV was detected in 10.2% and antibody to hepatitis B core antigen was detected in 44.4% of the patients, a significantly higher prevalence than found among matched controls. A multiple regression logistic analysis was used to identify risk factors that could indicate the route of infection by HCV. Duration of hospitalization, age, razor sharing, and history of surgery proved to be statistically significant independent risk factors associated with positive anti-HCV results [odds ratio (OR), 4.00; 95% confidence interval (CI), CI, 1.74-9.19; OR, 2.19; 95% CI, 1.27-1.3.77; OR, 4.90; 95% CI, 1.29-18.86; OR, 3.35; 95% CI, 0.997-11.3, respectively]. These observations suggest that razor sharing played an important role in the spread of the HCV infection in the institutionalized psychiatric patients we studied.

Hepatitis C antibody detection in dried blood spots.

In the UK, there have been few studies of the seroprevalence of antibodies to hepatitis C virus (anti-HCV). As part of an ongoing prevalence study of HCV in injecting drug users, we have developed a technique for detecting anti-HCV in blood spots dried on filter paper using a commercially available assay. Subjects with and without serum anti-HCV were studied. The manufacturer's recommended cut-off (CO) for a positive anti-HCV result is kit-dependent, and therefore a ratio of test result (T) to kit CO was used to standardize results. T/CO values greater than 0.99 had a sensitivity of 100% and a specificity of 87.5% for anti-HCV detection. T/CO values greater than 1.99 had a sensitivity of 97.2% and a specificity of 100%. Hence, testing dried blood spots may be useful for detecting anti-HCV in epidemiological studies and as a diagnostic test in patients with poor peripheral venous access.

Factors associated with positive predictability of the anti-HCV ELISA method with confirmatory RT-PCR.

The positive predictability of anti-HCV ELISA is low, especially, in blood donors and in healthy populations. False positive anti-HCV results pose some difficulties in medical practice and in blood screening. The aim of this study was to identify the factors associated with true hepatitis C virus (HCV) infection among anti-HCV ELISA-positives. A case-control analysis was conducted using 354 subjects who were positive for anti-HCV ELISA. All subjects were tested for true HCV infection using the reverse transcriptase polymerase chain reaction (RT-PCR). Tests for serum alanine aminotransferase (ALT), fasting glucose, HBsAg, anti-HBc antibody, alpha-fetoprotein, platelet count and ultrasound of liver were also performed. Epidemiological data were obtained by self-administered questionnaires. Out of 354 subjects, 202 (57.1%) were positive for HCV by RT-PCR and 152 were negative and used as the control group. In multivariate analysis, blood transfusion (odds ratio, OR 2.3, 95% confidence interval, CI 1.3-4.0), elevated ALT (OR 2.2, 95% CI 1.2-4.3) and higher anti-HCV ELISA ratios (more than 3; OR 1.7, 95% CI 1.3-2.1) were associated with true HCV infection. Thrombocytopenia was also associated with the presence of HCV in univariate analysis. These results suggest that a history of blood transfusion, elevated ALT and a high score on anti-HCV ELISA ratios are associated with true HCV infection among anti-HCV ELISA-positives.

Hepatitis C virus infection among institutionalised psychiatric patients: a regression analysis of indicators of risk

Background/Aims: Institutionalised psychiatric patients are at increased risk of developing chronic infection with hepatitis B virus (HBV). However, little information is available on transmission and epidemiology of hepatitis C virus (HCV) in this setting. The aim of this study was to identify potential risk factors of acquiring HCV infection in two large psychiatric institutions in northern Italy. Methods: We designed a case-control study using randomly selected controls from the same study database, consisting of a total of 1180 patients, in order to satisfy the principle that both cases and controls should be representative of the same base experience. A multiple regression logistic analysis was used to identify features that could predict exposure to HXV as evidenced by the presence of circulating anti-HCV antibodies. Results: Anti-HCV was detected in 79 patients (6.7%). The prevalence of viraemia and the distribution of genotypes were very similar to those found in subjects with chronic HCV infection drawn from the same geographical area. Multivariate analysis indicated that a diagnosis of psychosis and a history of trauma were statistically significant independent risk factors associated with a positive anti-HCV result (OR 2.615, 1.273—5.373 95% CI and OR 2.096, 1.133–3.877 95% CI, respectively). Conclusions: The findings of this large epidemiological study show for the first time that prolonged residence in psychiatric institutions does not entail per se a significant risk of acquiring HCV infection. Since transmission of HCV in this setting appears to occur predominantly via classical parenteral routes, simple prophylactic measures appear to be adequate to prevent infection.

Detection of hepatitis C viral sequences in serum by ‘nested’ polymerase chain reaction (PCR) and a commercial single-round PCR assay

Background: Demonstration of the hepatitis C virus (HCV) genome is usually done with combined reverse transcription and polymerase chain reaction (RT-PCR) employing nested primer sets. Recently, a commercial PCR assay (Amplicor PCR assay), based on a simplified sample preparation procedure, a single, combined reverse transcription and polymerase chain reaction (RT-PCR), and a microwell plate capture and detection, has been developed. Objective: The aim of the present study was to compare the new Amplicor assay with an ‘in-house’ PCR. Additional testing included a third-generation enzyme immunoassay for anti-HCV antibodies, the Wellcozyme HCV Western Blot, which is equivalent to a third-generation recombinant immunoblot assay. Furthermore, HCV genotypes were classified. Study design: Sera from a total of 127 patients were studied. After screening with a third-generation enzyme immunoassay (EIA), the Wellcozyme HCV Western Blot, was performed as well as the conventional RT-PCR and the Amplicor PCR. Specimens, which were found positive by testing with the Amplicor kit, were subjected to storage at room temperature for 96 h. Results: A total of 52 patients were found to be positive for anti-HCV by the third-generation EIA. With the Amplicor assay, the HCV genome was detected in 38 patients. In comparison with the ‘in-house’ assay, two discrepant results were found. Resolution of discrepant samples increased the total number of true positives to 39. A good correlation was found between a positive anti-HCV test result and the presence of HCV-RNA by RT-PCR. No significant reduction in the amount of amplification product was observed by retesting of suboptimally stored samples with the Amplicor assay. Conclusion: Because of the rapidity and the improved ease of handling, the Amplicor assay was found to be a good contribution for detection of HCV in serum.

Hepatitis B and C Viruses and Their Interaction in the Origin of Hepatocellular Carcinoma

Serum taken from patients in a case-control study in Athens, Greece, was used to examine the interactive roles of hepatitis B virus (HBV) and hepatitis C virus (HCV) in the origin of hepatocellular carcinoma (HCC). An enzyme immunoassay for anti-HCV was used to test serum taken from 185 cases with HCC, 35 cases with metastatic liver cancer (MLC), and 432 hospital controls. Weakly positive anti-HCV results were more strongly related to MLC than to HCC, implying that these anti-HCV results are false positive. By contrast, strongly positive anti-HCV results were significantly related to HCC (relative risk [RR], 6.3), whereas no significant association was evident for MLC (RR, 0.6). The association of anti-HCV with HCC was substantially higher among subjects whose radioimmunoassay was positive for hepatitis B surface antigen (RR, 20.0) than among those whose radioimmunoassay was negative for this marker (RR, 4.8). These findings indicate that HCV infection has an interactive role in the origin of HCC.

Does hepatitis C virus play a role in “non‐viral” chronic liver disease?

It has recently been suggested that the hepatitis C virus may play a significant role in chronic liver diseases, such as autoimmune chronic active hepatitis, which are usually attributed to non-viral causes. We tested for antibodies to hepatitis C virus (anti-HCV) in sera from 140 patients with well characterised "non-viral" chronic liver diseases as well as sera from 51 patients thought to have chronic non-A, non-B (NANB) hepatitis (acting as positive controls) and 25 patients with non-hepatic autoimmune disorders. As expected, 45 of 51 patients (88%) diagnosed as having chronic NANB hepatitis were anti-HCV seropositive. Among 26 patients with cryptogenic cirrhosis, 8 were anti-HCV seropositive; in 5 patients (22%) there was no apparent risk factor for parenteral transmission. In the remaining 114 patients with chronic liver disease, 10 patients (9%) were seropositive for anti-HCV. However, 5 of these patients had a significant risk factor for parenteral transmission of hepatitis C virus, leaving only 5 of 106 (4.7%) with unexplained positive anti-HCV test results. Among patients with high titres of circulating autoantibodies but no liver disease, no positive results occurred. It is concluded that hepatitis C virus infection may account for some cases of cryptogenic cirrhosis. Although anti-HCV occurs more commonly in patients with other "non-viral" chronic liver diseases than has been reported in the community (0.5%-1.2%), the low prevalence of the antibodies indicates that hepatitis C virus infection is unlikely to be important in the aetiology or pathogenesis of autoimmune chronic active hepatitis and other poorly understood chronic liver diseases.