Effect of male circumcision on the prevalence of high-risk human papillomavirus in young men: results of a randomized controlled trial conducted in Orange Farm, South Africa.

Background. A causal association links high-risk human papillomavirus (HR-HPV) and cervical cancer, which is a major public health problem. The objective of the present study was to investigate the association between male circumcision ( MC) and the prevalence of HR-HPV among young men. Methods. We used data from a MC trial conducted in Orange Farm, South Africa, among men aged 18-24 years. Urethral swab samples were collected during a period of 262 consecutive days from participants in the intervention (circumcised) and control (uncircumcised) groups who were reporting for a scheduled follow-up visit. Swab samples were analyzed using polymerase chain reaction. HR-HPV prevalence rate ratios (PRRs) were assessed using univariate and multivariate log Poisson regression. Results. In an intention-to-treat analysis, the prevalences of HR-HPV among the intervention and control groups were 14.8% (94/637) and 22.3% (140/627), respectively, with a PRR of 0.66 (0.51-0.86) (P =.002). Controlling for propensity score and confounders (ethnic group, age, education, sexual behavior [including condom use], marital status, and human immunodeficiency virus status) had no effect on the results. Conclusions. This is the first randomized controlled trial to show a reduction in the prevalence of urethral HR-HPV infection after MC. This finding explains why women with circumcised partners are at a lower risk of cervical cancer than other women.