CHANGE: Circumcision for AIDS prevention on the rise in Africa. “Unaids, the United Nations agency fighting the disease, said about 3.2 million African men had been voluntarily circumcised since word began spreading in 2007 of studies showing that it lowered the risk of infection by about 60 percent. . . . Circumcision is currently recommended for uninfected heterosexual men in countries where more than 1 percent of the population has H.I.V. It does not protect gay men engaged in receptive anal sex, believed to cause most infections in the United States.”