High prevalence of HCV in a cohort of injectors on methadone substitution treatment

Abstract

Background In Hong Kong, methadone treatment is widely accessible. Injecting drug users (IDU) have a relatively low risk behavioural profile and low HIV prevalence (0.3%). The corresponding Hepatitis C (HCV) level, however, is unclear. Objectives To determine the HCV prevalence in IDU in Hong Kong and to identify any associated factors. Study Design A community-based HCV prevalence study of IDU was conducted in methadone clinics. Demographics and drug use pattern were collected through a questionnaire survey and blood samples were obtained for HCV serological tests. Results Data of 567 IDU were analyzed. Most were male (84%) and ethnic Chinese (98%). The median age was 49 years and median injection duration 17 years. Two-thirds (62%) admitted ever sharing injecting equipments. Most (76%) reported having injection drug use in the preceding 3 months, and 44% abused midazolam/triazolam in addition to heroin. Prevalence of HCV antibodies was 85% (95% confidence interval 82.5–88.3%). Injection duration, recent injection, ever sharing injecting equipments and concomitant use of other drugs were independent factors associated with HCV infection. Conclusions HCV prevalence is high in IDU despite a low HIV prevalence and widely available substitution treatment, which has probably slowed but not prevented the HCV epidemic in IDU in Hong Kong.