Male circumcision reduces the risk of HIV transmission to female sexual partners by approximately one-third according to a study presented to the Thirteenth Conference on Retroviruses and Opportunistic Infections in Denver on February 8th. The investigators also found that circumcision reduces the risk of men infecting their female partners with some sexually transmitted infections.
Male circumcision has previously been shown to reduce the risk of a man becoming infected with HIV, but little is known about the effects of circumcision on the risk of transmission of HIV and other sexually transmitted infections to female sexual partners.
Investigators from the United States conducted an observational study involving individuals from the Rakai cohort in Uganda. The incidence of HIV infection was measured in 44 women with circumcised HIV-positive partners and 299 women with uncircumcised HIV-positive partners. Data were also collected on the incidence of syphilis, herpes simplex virus-2, gonorrhoea/chlamydia, human papilloma virus, bacterial vaginosis and trichomonas.
The incidence of HIV infection was just under seven infections per 100 person years for women with circumcised male partners compared to ten infections per 100 person years for women with uncircumcised partners. Although women with uncircumcised partners had a greater risk of being infected with HIV, the difference was not statistically significant (p = 0.22).
The female partners of circumcised and uncircumcised men were equally likely to be infected with syphilis, gonorrhoea and chlamyida. However, the investigators noted that the partners of circumcised men had a lower risk of human papilloma virus, herpes simplex virus-2, trichomonas and bacterial vaginosis.
Circumcision may reduce the risk of HIV transmission as removal of the foreskin mucosa reduces the exposure of sexual partners to HIV, the investigators speculate. Another explanation could be that circumcision reduces the risk of genital ulcerative disease such as herpes, a known risk factor for HIV infection.
“Male circumcision was associated with reduced risk of female HIV acquisition and lower risks of selected sexually transmitted infections”, conclude the investigators.
Gray R et al. Male circumcision and the risks of female HIV and sexually transmitted infections acquisition in Rakai, Uganda. Thirteenth Conference on Retroviruses and Opportunistic Infections, Denver, abstract 128, 2006.