HETEROSEXUAL TRANSMISSION OF HIV-INFECTIO N IN AQUITAINE - RESULTS OFA HOSPITAL-BASED SURVEILLANCE SYSTEM, 1985-1993

The goal of this article was to study the extent of HIV heterosexual t ransmission in the Aquitaine region, using data from a hospital-based HIV infection detection system. Three levels of heterosexual transmiss ion were considered: confirmed (defined according to AIDS reporting pr ocedures), probable, and possible. As of December 31, 1993, 13.4% of t he 3,586 HIV-infected subjects registered by the <<Groupe d'Epidemiolo gie Clinique du SIDA en Aquitaine>> (GECSA), were classified as infect ed through <<confirmed>> heterosexual transmission, 1.7% were classifi ed as infected through <<probable>> and 2.6% as infected through <<pos sible>> heterosexual transmission. Among confirmed and probable cases, the male to female ratio was 0.7:1. Over 85% of men and 65% of women were 25 years of age or more when diagnosed. The number of cases under 35 years of age decreased over time for both sexes. Heterosexual tran smission among asymptomatic subjects increased to 53% for women in 199 1, and 18% for men in 1990. It has levelled off since then. The propor tion of possible heterosexual transmission continued to increase for m en and women until 1993. Heterosexual males were mainly contaminated b y African women (25.7%) or drug users (22.9%). Heterosexual females we re primarily contaminated by male drug users (49.4%). Contamination by sexual contact with intravenous drug users appeared to be less and le ss frequent. The current definition of heterosexual transmission may u nderestimate the actual trends, because it does not take into account cases of probable or possible transmission. The relatively high propor tion of heterosexually acquired HIV infection among new diagnoses in A quitaine has to be taken into account; however the incidence of HIV in fection through heterosexual contacts remains low in the overall popul ation of our region.