A CASE-CONTROL STUDY OF HIV SEROCONVERSION IN GAY MEN, 1988-1993 - WHAT ARE THE CURRENT RISK-FACTORS

Objective: To investigate current risk factors for HN seroconversion a mong homo/bisexual men. Design: Matched case control study in a large STD clinic in central London. Data on risk factors were obtained by ca se note review. Methods: Fifty-six cases who had at least one negative HIV test followed by a positive test between June 1988 and July 1993, and two homo/bisexual controls (having two or more negative HN tests) matched to each case on age, total number of HIV tests and test inter val period were identified. Univariate and multivariate odds ratio wer e calculated for acute STD, ano-genital intercourse, condom use and HI V status of sexual partners. Results: Adjusted odds ratios (95% confid ence intervals) for HN seroconversion were 4.1 (1.3-13.3) for having a n acute interval STD and 4.6 (1.4-15.4) for having a known HIV infecte d sexual partner. Compared with men who always used condoms, odds rati os for men who sometimes or never used condoms were 7.9 (2.2-28.9) and 16.2 (3.0-86.0) respectively. Unprotected ano-genital intercourse was commonly reported by both cases and controls, and reported condom use was no greater with a known HIV infected partner than with a partner of unknown HIV status. Conclusion: HIV seroconversion among homo/bisex ual men attending STD clinics is strongly related to having an acute S TD, a known HIV infected partner and not using condoms. Although consi stent use of condoms is highly protective, knowing that a partner is H IV infected does not ensure condom use between serodiscordant men. Mor e effective, well-evaluated interventions are needed to reduce sexual risk-taking in this population.