Though it is hypothesized that circumcision does decrease the risk of contracting HIV in a single sexual encounter by 50-60%, after repeated exposures disease transmission is inevitable.
...John R. Talbott, has conducted statistical empirical research across 77 countries of the world and has uncovered some surprising results.Read his article here.
Talbott's new study suggests that the reason is that Africa as a whole has four times as many prostitutes as the rest of the word and they are more than four times as infected. Some southern Africa countries have as many as 7% of their adult females infected and working as prostitutes while in the developed world typically this percentage of infected prostitutes is less than .1%. If these 7% of infected prostitutes in Africa sleep with five men in a week that means they are subjecting 35% of the country's male population to the virus weekly.