HIV This Week

Auvert B, Sobngwi-Tambekou J, Cutler E, Nieuwoudt M, Lissouba P, Puren A, Taljaard D. 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. J Infect Dis. 2009;199(1):14-9.

A causal association links high-risk human papillomavirus and cervical cancer, which is a major public health problem. The objective of the present study was to investigate the association between male circumcision and the prevalence of high-risk human papillomavirus among young men. Auvert and colleagues used data from a male circumcision 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. High-risk human papillomavirus prevalence rate ratios were assessed using univariate and multivariate log Poisson regression. In an intention-to-treat analysis, the prevalences of high-risk human papillomavirus among the intervention and control groups were 14.8% (94/637) and 22.3% (140/627), respectively, with a prevalence rate ratio of 0.66 (0.51-0.86). Controlling for propensity score and confounders (ethnic group, age, education, sexual behaviour [including condom use], marital status, and human immunodeficiency virus status) had no effect on the results. This is the first randomized controlled trial to show a reduction in the prevalence of urethral high-risk human papillomavirus infection after male circumcision. This finding explains why women with circumcised partners are at a lower risk of cervical cancer than other women.

Editors’ note: With around 10% of all women worldwide having human papillomavirus (HPV) infection and 99.7% of all cervical cancers containing high-risk HPV, the finding that male circumcision reduces the prevalence of high-risk HPV in men is good news for women. No sampling was done before circumcision so it is not possible to draw conclusions about comparative high-risk HPV incidence in men who became circumcised versus those that did not. However, since HPV prevalence rises with age in men, the differences seen here are likely a good proxy of HPV incidence.

Male circumcision may lower men's risk of human papillomavirus infection and reduce transmission to sex partners. Reported associations between circumcision and human papillomavirus infection in men have been inconsistent. Four hundred sixty-three men in 2 US cities were tested at 6 anogenital sites and in semen for 37 types of human papillomavirus. Men were eligible if they reported sex with a woman within the past year, no history of genital warts or penile or anal cancer, and no current diagnosis of a sexually transmitted infection. Participants completed a self-administered questionnaire. Circumcision status was assessed by the study clinician. Logistic regression was used to examine associations between circumcision and human papillomavirus detection at each site and in semen, with adjustment for potential confounders. Seventy-four men (16.0%) were uncircumcised. Adjusted odds ratios for any human papillomavirus genotype and circumcision were 0.53 (95% confidence interval [CI], 0.28-0.99) for any anatomic site/specimen, 0.17 (95% CI, 0.05-0.56) for the urethra, 0.44 (95% CI, 0.23-0.82) for the glans/corona, and 0.53 (95% CI, 0.28-0.99) for the penile shaft. Adjusted odds ratios were <1.0 but not statistically significant for the scrotum, semen, anal canal, and perianal area. Circumcision may be protective against human papillomavirus infection of the urethra, glans/corona, and penile shaft.

Editors’ note: This is the first study to report associations between human papillomavirus (HPV) infection and circumcision at multiple, individually sampled, internal and external anogenital sites and semen. Circumcised heterosexual men were significantly less likely to have any HPV at key sites after adjusting for known HPV-related risk factors (smoking, lifetime number of sexual partners, and use of condoms for vaginal sex during the previous 3 months). In addition to further studies of HPV detection and persistence in relation to circumcision status, it is time to assess the cost-effectiveness of male circumcision for preventing HPV disease, as has been done for its role in reducing HIV acquisition in men.