Hepatitis C virus prevalence and outcomes among injecting drug users on opioid replacement therapy.

OBJECTIVES: To determine hepatitis C virus (HCV) prevalence among injecting drug users (IDUs) receiving opioid replacement therapy in a referred office setting, and assess potential needs for hepatitis C treatment and care.
METHODS: Data were collected on 178 IDUs receiving opioid replacement therapy who underwent clinical assessment between January 2002 and June 2003. Standard clinic protocols included HCV and hepatitis B virus (HBV) serology, liver biochemistry and HCV RNA analysis for patients with a positive HCV antibody and normal alanine aminotransferase (ALT) levels.
RESULTS: HCV prevalence was 75.3%, similar for males (75.5%) and females (74.4%), and increased with age from 60.8% for 19-30 years to 93.9% above 40 years. Among patients with HCV antibodies and no prior HCV antiviral therapy (n = 130), 53.1% had normal ALT levels and 25.4% were HCV-RNA negative. Older patients were more likely to have normal ALT levels (P = 0.02), and be HCV-RNA negative (P = 0.02). Younger patients were more likely to have been HBV vaccinated (P < 0.001), however, were less likely to have either vaccine or natural immunity (P = 0.006). Of 97 patients with probable chronic HCV infection, 58 patients met pre-liver biopsy criteria for HCV treatment, 34 had relative contraindications to treatment and 6 had been referred for treatment assessment.
CONCLUSION: Clinical characterization in a setting of high HCV prevalence has enabled the differentiation of patients into groups with no evidence of HCV viraemia, with chronic HCV infection, and those most appropriate for HCV treatment referral. These clinical assessments along with appropriate referral should be instituted in drug dependency treatment settings.