Infectious diseases and public health: risk-taking behavior during participation in the Swiss program for a medical prescription of narcotics (PROVE).

The medically controlled prescription of narcotics program (PROVE) followed a uniform protocol from January 1, 1994 until December 31, 1996. The program included 800 slots for heroin prescription, 200 slots for intravenous methadone prescription, and 200 slots for intraveneous morphine. Admission criteria were age 20 and above, minimum 2-year duration of daily heroin consumption, failure in at least two previous treatments, and documented social and/or health deficits. There was a very high seroprevalence of hepatitis B (73%) and hepatitis C (82%) among the 1035 entrants. The rate of HIV (15%) was also high compared with prevalence of infection in other therapy programs (methadone program, inpatient therapy). The prevalence of HIV and hepatitis B/C increased with the duration of drug dependence and cocaine use. During treatment, use of street heroin and cocaine could be reduced substantially. After 18 months of continued participation in the program, 74% of patients reported no illegal heroin consumption, and the rate of cocaine abstinence increased from 15% at entry to 41%. Significant declines in visits to the drug scene, illegal income, and needle sharing were also observed. The high prevalence of HIV and hepatitis B and C confirm that a group of drug dependence with severe medical problems was reached in accordance with the admission criteria for the studies. During treatment, a significant reduction in risk-taking behavior was observed in a target population of heroin-dependent persons who failed in previous treatments.