Over forty epidemiological studies have been conducted to investigate the relationship between cir
cision and HIV infection.Reviews of these studies have reached differing conclusions about whether cir
cision could be used as a prevention method against HIV.
Experimental evidence was needed to establish a causal relationship between lack of cir
cision 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,Kenyaand Uganda. All three trials were stopped early by their monitoring boards on ethical grounds, because those in the cir
cised group had a lower rate of HIV contraction than the control group. The results showed that cir
cision 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 cir
cised males was 0.44 times that in uncir
cised males, and that 72 cir
cisions would need to be performed to prevent one HIV infection. The authors also stated that using cir
cision 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 cir
cision 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 cir
cision 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 cir
cision only provides partial protection from HIV and should never replace known methods of HIV prevention.
Cir
cision has been judged 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 cir
cision as an HIV prevention strategy.