HIV prevalence among clients attending a sexually transmitted diseases clinic in Amsterdam: the potential risk for heterosexual transmission.
INTRODUCTION--Patients attending a clinic for sexually transmitted diseases (STD) in general have engaged in at risk sexual behaviour. Therefore they are at increased risk of acquiring HIV through sexual contact. OBJECTIVE--To determine the HIV prevalence among patients attending a STD clinic in Amsterdam. METHODS--An anonymous cross sectional study was conducted in two 5-week periods in Spring and Autumn 1991. RESULTS--Of the 2362 patients attending the clinic during the study period, 2292 (97%) consented to participate; of these, 2138 (93%) were interviewed and anonymously tested, while 154 (7%) consented to be interviewed but refused HIV antibody testing. The HIV prevalence was 4.2% (90/2138); 93% of seropositive participants reported homosexual contacts and/or intravenous use of drugs (IVDU). HIV prevalence among heterosexual non-IVDU men was 0.5% and among non-IVDU women 0.1%. Among all heterosexually active participants, including IVDU and bisexual men, the HIV prevalence was 1.5%. The 28 of 90 HIV infected participants that were heterosexually active reported together approximately 135 heterosexual partners in the six months preceding the study; 13 of these 28 heterosexually active participants had a STD diagnosed at their present clinic visit, while four (30%) of them already knew they were HIV infected. CONCLUSIONS--From these data we conclude that there is a substantial risk of further transmission of HIV through heterosexual contact. In order to try to reduce this potential for further sexual transmission of HIV, services offered by the STD clinic should not only include voluntary confidential counselling and HIV testing, but also notification of partners of HIV infected clinic-attendants. Finally, we conclude that anonymous HIV prevalence studies that link HIV test results to risk behaviour for HIV infection can be performed with a high rate of participation. Repeating such prevalence studies in time can help in monitoring the HIV incidence in the heterosexually active population.