Decreased incidence of syphilis in both men and women associated with male circumcision: a prospective study among HIV-1 serodiscordant heterosexual African couples

Abstract

Abstract Background: Male circumcision is a primary HIV-1 prevention intervention for men. It is uncertain whether male circumcision reduces the risk of syphilis among men and their female partners. Methods: Using data from a prospective study among HIV-1 serodiscordant heterosexual couples from Kenya and Uganda, we assessed whether male circumcision was associated with incident syphilis in men and in their female partners. Multivariate Andersen-Gill survival methods were used. Results: 4716 HIV-1 serodiscordant couples (37.5% with an HIV-1 infected male) were followed for a median of 2.75 years. At enrollment, 1575 (53.5%) HIV-1 uninfected and 560 (32.4%) HIV-1 infected men were circumcised; 69 (4.2%) HIV-1 infected and 132 (4.8%) HIV-1 uninfected men were circumcised during study follow up. In couples where the male was HIV-1 infected, after adjustment for sexual behavior, age, and HIV-1 viral load of the HIV-1 infected partner, male circumcision was associated with a 62% reduction in incident syphilis in the HIV-1 infected male partner (adjusted hazard ratio (HR) 0.38, 95% CI 0.18-0.81) and a 75% reduction in incident syphilis in the HIV-1 uninfected female partner (adjusted HR 0.25, 95% CI 0.08-0.76). In couples where the male was HIV-1 uninfected, male circumcision was associated with a 36% reduction in incident syphilis in the HIV-1 uninfected male partner (adjusted HR 0.64, 95% CI 0.36-1.11, not statistically significant) and a 48% reduction in incident syphilis in the HIV-1 infected female partner (adjusted HR 0.52, 95% CI 0.27-0.97). Conclusions: In this large prospective cohort study among HIV-1 serodiscordant couples, male circumcision was associated with decreased risk of incident syphilis in both men and women. If confirmed, these results suggest that medical male circumcision could substantially reduce incidence of syphilis and its sequelae.