Abstract
When human immunodeficiency virus type 1 (HIV-1) was identified as the cause of AIDS more than 15 years ago, it seemed possible that an end to the epidemic would follow. However, the control of communicable diseases requires far more than the identification of causative pathogens. It also requires an understanding of the ways in which a pathogen is spread; an understanding of the biologic, behavioral, and social requirements for transmission; the development of both biologic and behavioral approaches to prevention; the mobilization of social and political forces; and money. Perhaps no disease has highlighted the importance of these requirements more . . .