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 (anuary 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 conclusion, our study confirms the emerging role of heterosexuals in the current HIV epidemic. People older than teenagers seem to have misperceived their own risk of HIV infection, given the increase in the mean age occurred in the most recent years. This trend suggests the need for prevention strategies focusing more on heterosexual transmission and older people.