Antibody to hepatitis C virus in risk groups in Canada

Analysis of risk factors associated with hepatitis B and C infection in correctional institutions in British Columbia

The factors associated with infection with hepatitis B (hbv) and C viruses (hcv) were studied in residents of correctional institutions in British Columbia. Four hundred and fifteen residents volunteered to participate in this study. Among 415 residents tested, 28% were positive for hvb or hcv markers. Sixty-five per cent of the residents positive for hbv markers were also infected with hcv. However, in hbv-negative residents, only 14% were positive for antibody to hcv (anti-hcv). The highest rates for hbv and hcv were in 25- to 44-year-old residents. The analysis of risk factors and infection predictors in 354 residents showed that intravenous drug use and history of hepatitis were associated with infection with both hbv and hcv. The relative risk for hbv in intravenous drug users was 4.4 times that in nonusers; for hcv relative risk was 3.4 times. In the group with history of hepatitis, the relative risk was 6.2 and 4.5 times for hbv and hcv, respectively. The multivariate analysis of the data showed that both intravenous drug use and a history of hepatitis were significant (P<0.0001). Tattooing or history of transfusion was not associated with increased risk for hcv, but tattooing and age were significant factors for hbv.

Distribution of hepatitis C virus genotypes in Canada: Results from the LCDC Sentinel Health Unit Surveillance System

In a sentinel hepatitis surveillance study conducted by sentinel health units, 1469 patients were enrolled, and 959 (65.3%) were positive for antibody to hepatitis C virus (HCV). Samples from 387 patients (40.4%) were tested for HCV RNA, and 289 (74.7%) were positive for RNA. The major risk factor for HCV infection was injection drug use, reported in 71% of cases. The genotyping of HCV isolates showed that subtype 1a (48%) was predominant in Canada. The other subtypes detected were 1b (19%), 2a (6%), 2b (3%), 3a (22%) and 4a (1%). In Winnipeg, Manitoba, subtype 3a (47%) was more prevalent than subtype 1a (37%), and, in Guelph, Ontario, both subtypes 1a and 3a had equal (40%) distribution. The prevalence of subtype 3a was significantly higher in injection drug users (27%) than in nonusers (10%) (P<0.005). In Canada, injection drug use is the major risk factor for HCV infections, and subtype 1a is more prevalent.

Viral hepatitis in a Canadian street-involved population

BACKGROUND

Data on the prevalence and compliance with management of viral hepatitis in the street-involved population are limited.

METHOD

Hepatitis A (HAV), B (HBV) and C (HCV) serology and compliance with HBV vaccination were documented in 533 street-involved individuals.

RESULTS

The mean age of the study population was 25.7 years (range: 11-65) and 53% were female. Serologic evidence of HAV infection was present in 53%; HBV, 12% (3% ongoing infection); and HCV, 17%. HAV infections were associated with Aboriginal/Metis ethnicity and age over 25 years; HBV with injection drug use (IDU); and HCV with IDU, sex trade work and age over 25 years. Compliance with three-step HBV vaccination was 98%, 77% and 63%.

CONCLUSIONS

HAV, HBV and HCV are common infections in urban street-involved persons. Successful HBV (and presumably HAV) vaccination can be achieved in the majority of this population, but concerns exist regarding compliance with more long-term, parenterally-based antiviral therapies.

Transmission of hepatitis C in a pharmacologic study

OBJECTIVE

To describe an outbreak of hepatitis C in a clinical research study.

DESIGN

Observational study.

SETTING

Tertiary-care hospital.

PATIENTS

Healthcare workers who volunteered to be subjects in a study of the metabolic effects of inhaled and oral corticosteroids who were unwittingly exposed to hepatitis C virus (HCV).

METHODS

Epidemiological investigation and serological analyses.

RESULTS

One chronic carrier of HCV was identified. Four fellow workers volunteering in the studies became infected with HCV, with 96% homology among strains. There was no evidence of spread from infected healthcare workers to patients on whom they had performed arterial punctures (2 of 214 positive, unrelated to each other and to the outbreak strain).

CONCLUSION

Infection control standards in clinical research must be maintained vigorously to prevent transmission of blood-borne pathogens such as HCV.

Detection of hepatitis C virus infection with recombinant immunoblot assay, synthetic immunoblot assay, and polymerase chain reaction

The newly developed immunoblot assay, RIBA SIA (recombinant and synthetic polypeptide immunoblot assay), Chiron, Calif., was compared with the commercially available second generation recombinant immunoblot assay (RIBA-2) for the detection of antibody to hepatitis C virus (anti-HCV). The two immunoblot tests were also compared with the polymerase chain reaction (PCR) for the detection of HCV RNA. Ninety-one percent of samples reactive by RIBA-2 were positive for anti-HCV by RIBA SIA. A total of 31% of RIBA-2 indeterminate samples became reactive by RIBA SIA, 24% became non-reactive, and 45% remained the same. Samples reactive by RIBA-2 or SIA from different risk groups, were mostly positive (67-100%) by PCR for HCV RNA. All indeterminate samples from hemophiliacs and intravenous drug users were PCR positive. RIBA SIA is more sensitive and specific than RIBA-2 and correlates well with PCR results.