Prevalence of hepatitis C among injecting drug users attending drug clinics.

Background: Chronic hepatitis C (HCV) infection is an important public health issue in New Zealand, and an increasing cause of advanced liver disease.

Method: This study examined the 2015 data on hepatitis C serology in patients on opiate substitution at four Alcohol and Drug Services, as well as rates of referral and responses to treatment for HCV.

Results: Among 579 patients tested, 439 (76 %) were positive for HCV antibody. For a subgroup of patients, those who reported their first use of injecting since 2010, the prevalence of HCV antibody was 48%. Among 405 patients with PCR/viral load test on file, 206 had a positive result when most recently tested. In all, 191 patients were referred for treatment, and of the 91 treated, 68 achieved viral clearance. Overall, it was found that 131 (32%) patients with a PCR/viral load test on file had cleared the HCV without treatment, as indicated by at least one negative PCR.

Conclusions: HCV remains highly prevalent in injecting drug users attending these clinics, with no important reduction in infection rates from past studies. There appears to be considerable rates of spontaneous viral clearance. Nevertheless, it remains important, from individual and public health perspectives, to refer patients for treatment, which is becoming increasingly effective and safe.