Human immunodeficiency virus (HIV) infection and AIDS affect 42 million people worldwide. If the current projections are correct, 100 million more people will contract the disease by the end of the decade, and 45 million more people will die from AIDS-related illnesses. Some compare the AIDS pandemic to the bubonic plague in the 14th century, which wiped out one third of Europe. The key difference, in my mind, between these two pandemics is that this time we are able to do something about it.