[HIV surveillance in an outpatient clinic for sexually transmissible diseases in Amsterdam, 1991-1994; low and stable prevalence among heterosexual clients].

Objective: To assess the HIV prevalence among heterosexual attenders of a clinic for sexually transmitted diseases (STD) and among subpopulations, including young gay men and ethnic minorities.
Setting: Outpatient clinic for sexually transmitted diseases (STD) of the Municipal Health Service of Amsterdam, the Netherlands.
Methods: Semi-annually in the period 1991-1994, blood samples given voluntarily and anonymously were tested for HIV antibodies and some characteristics were collected of approximately 1000 clinic attenders.
Results: Since 1991, 6766 clinic attenders were eligible for participation, of whom 6200 (92%) were actually tested. The overall HIV prevalence decreased from 3.9% in the first half of 1991 to 2.3% in the second half of 1994. Among heterosexual clinic attenders the prevalence remained stable below 1%, due mainly to visitors from abroad rather than to Dutch heterosexuals: 20 of the 23 HIV infected heterosexuals were not Dutch. None of these 23 seropositive persons knew of their HIV infection, mostly because they had not been tested previously. The HIV prevalence among gay men decreased over the years. In addition, the number of gay male attenders younger than 30 years decreased strongly over time.
Conclusions: HIV infections among heterosexual STD clinic attenders are relatively few and are seen mainly among non-Dutch. We found no indications of an increase of the HIV prevalence among heterosexual clinic attenders. The results among young gay men are suggestive of a shift towards safer sexual behaviour in this group.