PREVALENCE AND INCIDENCE RATE OF HIV, HEPATITIS-B AND HEPATITIS-C AMONG DRUG-USERS ON METHADONE-MAINTENANCE TREATMENT IN GENEVA BETWEEN 1988 AND 1995

Objectives: To evaluate the prevalence and incidence rates oi infectio n with HIV, hepatitis B (HBV) and hepatitis C (HCV), in a cohort of dr ug users (DU) in Geneva, Switzerland. Design: Prospective open cohort study. Setting: Private methadone maintenance treatment (MMT) programm e. Patients, participants: Over 700 DU in treatment between 1988 and 1 995 were tested biannually for HIV, HBV and HCV infection. Interventio n: None. Main outcome measure: Prevalence for HIV, HBV and HCV at stud y entry, determined by gender, by injection behaviour, by year of star t of MMT and incidence rates for HIV, HBV and HCV, assuming equal risk of seroconversion on each day of the interval between last negative a nd first positive test. Results: The prevalence at entry into treatmen t declined dramatically over time for all three viruses. Comparing DU entering treatment before 1988 to those entering treatment after 1993, the prevalence of HIV was 38.2% versus 4.5%, of HBV 80.5% versus 20.1 %, and of HCV 91.6% versus 29.8%, respectively. Follow-up rate was 80% . The incidence rates for HIV and HBV were 0.6% and 2.1% per person-ye ar of follow-up, respectively. For HCV the rate was higher (4.2%) espe cially among women (9.6%). Conclusion: These data suggest that DU have changed HIV risk-taking behaviour in response to HIV prevention campa igns. Current prevention efforts should focus on improvement of HCV pr evention, identification of high-risk individuals and maintaining safe behaviour. (C) 1998 Lippincott Williams & Wilkins.