From an article in Discover magazine (boldface mine):

Every major campaign against AIDS in Africa has been based on the premise that heterosexual sex accounts for 90 percent of transmission in adults. Yet safe-sex efforts have not stopped the spread of the epidemic, which now affects 30 million people. Economic anthropologist David Gisselquist therefore suspected that HIV might be spreading primarily by another route. After analyzing 20 years of epidemiological studies, he and his colleagues concluded that unsafe injections, blood transfusions, and other medical procedures may account for most AIDS transmission in African adults. Their analysis indicates that no more than 35 percent of HIV in that population is spread through sex.

That was news to me. If this is true, and assuming this is not old news to experts in the field, it means that a lot of the efforts to stop AIDS in Africa may have been barking up the wrong tree, and future efforts may be no different. I blame conservatives for only looking at AIDS as a moral issue, and I blame liberals for being overly eager to show Africa as a case study proving that AIDS can be rampant in non-drug-using heterosexuals.

It sounds to me like what is needed is a huge reform in how medical equipment is used in Africa, and maybe some of that $15 billion can go in that direction.