The epidemiology of human immunodeficiency virus infection

The epidemiology and natural history of infection with the human immunodeficiency virus (HIV) is reviewed. HIV is associated with a broad spectrum of disease, including AIDS. In presenting the natural history, early and late clinical manifestations, diagnosis of infection, incubation and latency periods, and survival time are discussed. Data from the published literature on the distribution of HIV infection in the adult U.S. population and factors that affect the acquisition and spread of the virus are also reviewed. Understanding of the epidemiology of this infection in certain high-risk groups is substantial and has provided a clear focus for preventive efforts and counseling. Many questions about spread in heterosexuals and about factors that may affect the natural history of the disease await completion of ongoing and planned studies.