Male circumcision could avert millions of HIV infections.

In the next 10 years, universal circumcision of men and boys in sub-Saharan Africa could prevent 2 million new cases of infection with the human immunodeficiency virus (HIV) and avert 300,000 deaths. Over the following 10 years, it could prevent 3.7 million additional HIV infections and 2.7 million more deaths.

The estimates, reported in the July PLoS Medicine, include women because they would be less likely to get infected if fewer men were HIV-positive, says coauthor Brian G. Williams, an epidemiologist at the World Health Organization in Geneva, Switzerland.

Last year, researchers reported that circumcision reduces by more than half the risk of a sexually active man acquiring HIV (SN: 10/29/05, p. 275). By removing the foreskin, the procedure eliminates cells that are easily infected.

Williams' team says that one-quarter of the lives saved would be in South Africa, where only about one-third of males are circumcised and nearly 25 percent of adults are infected with HIV. Much of the remaining improvement would be in countries in eastern and southern Africa that have even lower circumcision rates.

The full impact of such a program "wouldn't be seen for 15 to 20 years," Williams cautions. -- N.S.