Changing patterns of HIV transmission and better targeting for intervention strategies.

We considered the HIV population of our area, comparing demographic characteristics between 2 consecutive 6-year periods to assess the current patterns of HIV transmission. All HIV-positive patients referred to our hospital from January 1985 to December 1996 were included in the study and were classified into 2 periods: A (January 1985 to December 1990) and B (January 1991 to December 1996). The variables analysed were: sex, age at first visit, HIV risk category. A total of 4284 HIV subjects were observed, 2306 in period A vs 1978 in period B (P=ns). Males were 76.3% vs 75.2% (P=ns). Mean age for males was 27.4 vs 32.4 years (P < 0.001) and for females 25.4 vs 30.1 years (P < 0.001). Intravenous drug users (IVDUs) were 88.4% vs 65.4% (P < 0.001), 'heterosexuals' 14.3% vs 24.8% (P < 0.001), 'men who have sex with men' 2.4% vs 4.8% (P < 0.001). Mean age by the main risk groups was: IVDUs 25.9 vs 29.7 years (P < 0.001); heterosexuals 30.4 vs 36 years (P=0.007); 'men who have sex with men' 35 vs 35 years. In ...