Trends in HIV prevalence among drug-users attending public drug-treatment centres in Italy: 1990-2000.

The occurrence of HIV infection among drug-users in Italy between 1990 and 2000 is described; the data concern drug-users attending a nation-wide network consisting of 510 public drug-treatment centres. We included only individuals with written documentation of an HIV-test result. Of the 1,299,972 attendees, 54.5% had a documented HIV-test result. The overall HIV prevalence among those with a test result was 19.8%. The annual prevalence decreased from 30.8% in 1990 to 15.8% in 2000 (chi-square for linear trend P < 0.0001); the decrease was more evident between 1990 and 1996, whereas the prevalence apparently levelled-off after 1996. The annual prevalence was significantly higher among females compared to males throughout the study period. The annual prevalence was consistently three to four times higher for prior attendees, compared to new entrants. Although information on whether or not the attendees injected drugs was not available for the entire study period, the proportion of attendees with a documented HIV-test result can be considered as an approximation of the proportion who inject drugs. Although HIV infection was widespread among injecting drug-users in Italy beginning in the mid-1980s, since the early 1990s it has been somewhat contained. However, the levelling-off of the prevalence after 1996 may conceal an increase in the number of new infections and should be more thoroughly investigated. Aggregated national-level data, despite their limitations, represent a reliable tool for monitoring the temporal trend of HIV prevalence among injecting drug-users in Italy. Copyright 2004 Wiley-Liss, Inc.