DECLINE OF AN EPIDEMIC - HIV IN DRUG-ABUS ERS IN GENEVA, 1988-1994

Of Geneva's 395 000 inhabitants, 1100 are drug addicts substituted wit h methadone, Seventy-eight percent of AIDS patients in Geneva infected by intravenous drug abuse, had previously been enrolled in methadone programs. The present investigation was conducted in 4 methadone treat ment centres in Geneva, in order to measure seroprevalence levels for blood-borne viruses, needle sharing, and sexual habits, Among particip ants starting methadone, seroprevalence rates for HIV decreased from 5 2% in 1984/1985 to 8 percent in 1992/1994 (p < 10(6)), Seroprevalence for markers of hepatitis 8 (65% in 1989, 48% in 1994, p < 10(6), and h epatitis C (80% in 1989, 55% in 1994, p < 10(6)) also decreased. Among patients on methadone, 8 seroconversions were observed in 1070 patien t-years of observation, yielding an incidence of 0.75% per year (confi dence interval 0,32 to 1.47%), Needle sharing had almost completely st opped by 1994, although 46% of patients on methadone continued to inje ct heroin during the six months preceding the investigation, ''Always' ' use of condoms increased from less than 10% before 1986 to 30% among HIV-negatives and 65% among HIV-positives. Ninety-three percent of th ose who did not always use condoms claimed to know that their partner( s) is (are) HIV-seronegative.