Public health officials have been urging circumcision on men in sub-Saharan Africa, arguing that the universal application of the practice could prevent two million HIV cases a year. A recent study in Zambia, however, shows that roughly a quarter of newly circumcised men resume sexual activities before they have fully healed, facilitating the spread of the virus. As a result, health experts fear that the spread of circumcision in the region could actually increase HIV infection rates.