How does male circumcision protect against HIV infection?
Uncircumcised men are at a much greater risk of becoming infected with HIV than circumcised men, according to new evidence in this week's BMJ.
Using information from over 40 previous studies, researchers in Australia suggest that the virus targets specific cells found on the inner surface of the foreskin. These cells possess HIV receptors, making this area particularly susceptible to infection. The researchers propose that male circumcision provides significant protection against HIV infection by removing most of the receptors.
The most dramatic evidence of this protective effect comes from a new study of couples in Uganda, where each woman was HIV positive and her male partner was not. Over a period of 30 months, no new infections occurred among 50 circumcised men, whereas 40 of 137 uncircumcised men became infected - even though all couples were given advice about preventing infection and free condoms were available to them.
Although cultural and religious attitudes towards male circumcision are deeply divided, the authors conclude that, in the light of the evidence, male circumcision should be seriously considered as an additional means of preventing HIV in countries with a high level of infection. Alternatively, say the authors, the development of 'chemical condoms' - products which can block HIV receptors in the penis and the vagina - might provide a more acceptable form of HIV prevention in the future.
Contact:
Professor Roger Short, Department of Obstetrics and Gynaecology, University of Melbourne, Royal Women's Hospital, 132 Grattan Street, Melbourne 3053, Australia