Circumcision and HIV

Over forty observational studies have been conducted to investigate the relationship between circumcision and HIV infection. Reviews of these studies have reached differing conclusions about whether circumcision could be used as a prevention method against HIV.

Experimental evidence was needed to establish a causal relationship between lack of circumcision and HIV, so three randomized controlled trials were commissioned as a means to reduce the effect of any confounding factors. Trials took place in South Africa, Kenya and Uganda. All three trials were stopped early by their monitoring boards on ethical grounds, because those in the circumcised group had a lower rate of HIV contraction than the control group. The results showed that circumcision reduced vaginal-to-penile transmission of HIV by 60%, 53%, and 51%, respectively. A meta-analysis of the African randomised controlled trials found that the risk in circumcised males was 0.44 times that in uncircumcised males, and that 72 circumcisions would need to be performed to prevent one HIV infection. The authors also stated that using circumcision as a means to reduce HIV infection would, on a national level, require consistently safe sexual practices to maintain the protective benefit.

As a result of these findings, the WHO and the Joint United Nations Programme on HIV/AIDS (UNAIDS) stated that male circumcision is an efficacious intervention for HIV prevention but should be carried out by well trained medical professionals and under conditions of informed consent. Both the WHO and CDC indicate that circumcision may not reduce HIV transmission from men to women, and that data is lacking for the transmission rate of men who engage in anal sex with a female partner. The joint WHO/UNAIDS recommendation also notes that circumcision only provides partial protection from HIV and should never replace known methods of HIV prevention. Male Circumcision Clearinghouse website was formed by WHO, UNAIDS, FHI and AVAC to provide current evidence-based guidance, information and resources to support the delivery of safe male circumcision services in countries that choose to scale up male circumcision as one component of comprehensive HIV prevention services.

Circumcision has been judged by the WHO to be a cost-effective method to reduce the spread of HIV in a population, though not necessarily more cost-effective than condoms. Some have challenged the validity of the African randomized controlled trials, prompting a number of researchers to question the effectiveness of circumcision as an HIV prevention strategy.
In addition to the studies which provided information about female-to-male transmission, some studies have addressed other transmission routes. A randomised controlled trial in Uganda found that male circumcision did not reduce male to female transmission of HIV. The authors could not rule out the possibility of higher risk of transmission from men who did not wait for the wound to fully heal before engaging in intercourse. A meta-analysis of data from fifteen observational studies of men who have sex with men found "insufficient evidence that male circumcision protects against HIV infection or other STIs."

http://en.wikipedia.org/wiki/Circumcision#Medical_aspects