Does voluntary medical male circumcision protect against sexually transmitted infections among men and women in real-world scale-up settings? Findings of a household survey in KwaZulu-Natal, South Africa

Introduction Male circumcision (MC) confers partial protection to men against HIV and, in research settings, some sexually transmitted infections (STIs). It is also associated with protection from some STIs among female partners. However, real-world data on changes in STI transmission associated with large-scale public African medical male circumcision (MMC) conducted for HIV prevention are lacking and would improve estimates of the health impact of MMC. Methods The HIV Incidence Provincial Surveillance System is a community-based surveillance platform for HIV prevalence, incidence and intervention coverage trends in KwaZulu-Natal province, South Africa. HIPPS collected cross-sectional self-reported data on circumcision status (from men), partner circumcision status for past three partners (from women) and demographic characteristics and behavioural risk factors; and tested participants for HIV, herpes simplex virus type 2 (HSV-2), syphilis, hepatitis B, Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and Mycoplasma genitalium. Bivariable and multivariable analyses were performed on associations between own (men) or partner's (women) circumcision status and each STI. Multivariable analyses adjusted for age, demographic characteristics and behavioural risk factors, and incorporated false discovery rate (FDR) correction. Results Among men, MMC had a protective association with HSV-2 (OR 0.66, 95% CI 0.50 to 0.86), hepatitis B (OR 0.53, 95% CI 0.30 to 0.95), HIV (OR 0.50, 95% CI 0.38 to 0.65) and M. genitalium (OR 0.53, 95% CI 0.32 to 0.88). Among women, partner circumcision had a protective association with HSV-2 (OR 0.71, 95% CI 0.53 to 0.95) and HIV (OR 0.66, 95% CI 0.49 to 0.90). Associations with HIV and HSV-2 remained significant for men and all women after FDR correction. Conclusion These real-world data, supporting protective associations between MMC conducted for HIV prevention and STIs in men and women, can help clarify the full impact of MMC and support a role in broader sexual health programming.