Male circumcision and HIV acquisition and transmission: cohort studies in Rakai, Uganda

Background: Male circumcision is associated with reduced HIV acquisition. Methods: HIV acquisition was determined in a cohort of 5507 HIV-negative Ug andan men, and in 187 HIV-negative men in discordant relationships. Transmi ssion was determined in 223 HIV-positive men with HIV-negative partners. HI V incidence per 100 person years (py) and adjusted rate ratios (RR) and 95% confidence intervals (CI) were estimated by Poisson regression. HIV-1 seru m viral load was determined for the seropositive partners in HIV-discordant couples. Results: The prevalence of circumcision was 16.5% fbr all men; 99.1% in Mus lims and 3.7% in non-Muslims. Circumcision was significantly associated wit h reduced HIV acquisition in the cohort as a whole (RR 0.53, CI 0.33-0.87), but not among non-Muslim men. Prepubertal circumcision significantly reduc ed HIV acquisition (RR 0.49, CI 0.26-0.82), but postpubertal circumcision d id not. In discordant couples with HIV-negative men, no serconversions occu rred in 50 circumcised men, whereas HIV acquisition was 16.7 per 100 py in uncircumcised men (P = 0.004). In couples with HIV-positive men, HIV transm ission was significantly reduced in circumcised men with HIV viral loads le ss than 50 000 copies/ml (P = 0.02). Interpretation: Prepubertal circumcision may reduce male HIV acquisition in a general population, but the protective effects are confounded by cultura l and behavioral factors in Muslims. In discordant couples, circumcision re duces HIV acquisition and transmission. The assessment of circumcision for HIV prevention is complex and requires randomized trials. (C) 2000 Lippinco tt Williams & Wilkins.