Today I came across an article in The Economist that relates Circumcision and HIV.
The XVIIth International AIDS Conference | Win some, lose some | Economist.com.
It was this sort of careful science—starting with a scientific hypothesis, following it up with observations in the field and ending with clinical trials—which proved that circumcision protects against infection. Indeed, amid the gloom about microbicides and vaccines, circumcision is the one bright spot in the field of AIDS prevention. Most forms of prevention have to be pushed on to people. But there are already parts of Africa, including South Africa, Swaziland and Zambia, where men are queuing up to have their foreskins cut off. The scientific basis of all this is that foreskin tissue is rich in a particular sort of cell that HIV likes very much. The field observation is that, within Africa, one of the two best predictors of the intensity of the epidemic in any given place is the prevalence of circumcision. The clinical trials suggest that circumcision by itself reduces a man’s chance of becoming infected by 50-60%. The upshot, according to Brian Williams of the World Health Organisation, is that if, in some ideal world, every sexually active man in sub-Saharan Africa were circumcised, 2m new infections would be avoided over the course of ten years, and 300,000 deaths prevented.