sentences:  Some experimental evidence has been provided to support these theories.The WHO and the UNAIDS state 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 (parents' consent for their infant boys).The WHO has judged circumcision to be a cost-effective public health intervention against the spread of HIV in Africa, although not necessarily more cost-effective than condoms.