Circumcision and male-to-male sexual transmission of HIV

In recent years, evidence from observational studies in sub-Saharan Africa has shown that circumcised men have a lower risk of acquiring HIV infection than uncircumcised men. The proposed mechanism by which the circumcised state might protect against HIV infection is twofold. First, the inner surface of the foreskin contains Langerhans cells, which have HIV receptors, and is also vulnerable to traumatic epithelial disruptions during intercourse. Second, an intact foreskin exposes a man to a greater risk of ulcerative sexually transmitted infections, which in themselves are a risk factor for HIV acquisition. The evidence that circumcision may protect against HIV infection is now considered strong enough that trials evaluating the efficacy of circumcision as part of an HIV prevention package have been advocated. Almost all of the literature suggesting that circumcision protects against HIV infection in men has been conducted in heterosexual individuals, mostly in developing countries. We examined the relationship between circumcision and HIV transmission in homosexual men in Sydney, Australia.