THE EPIDEMIOLOGY OF THE HUMAN-IMMUNODEFICIENCY-VIRUS

During the past decade, AIDS has become a global health problem with 182,000 cases reported from 152 countries. It is estimated that nearly five to ten million people are infected worldwide with the etiologic agent of AIDS, human immunodeficiency virus type 1 (HIV-1). With a mean incubation period from time of infection to the development of AIDS of eight to ten years, it is projected that nearly all HIV-1-infected individuals will develop AIDS within the next 15 years. In the United States alone, 104,210 cases of AIDS and more than 61,000 deaths have been reported. Sexual, parenteral, and perinatal transmission routes have remained the major modes of transmission, although the proportion of cases within each risk behavior category has changed. Recently, there has been a dramatic increase in the proportion of patients with AIDS who have acknowledged either IV drug use or heterosexual contact with other individuals at high risk for HIV infection. Inner-city minority populations are disproportionately represented among AIDS patients, and HIV-seroprevalence studies demonstrate significantly higher rates of infection among blacks and Hispanics compared with whites, even within the same risk category. In 1988, the US Public Health Service estimated that approximately 1.0 to 1.5 million Americans were currently infected with HIV-1 and that by the end of 1992, a cumulative total of 380,000 cases of AIDS will be diagnosed. In 1992, 80,000 cases of AIDS may be diagnosed, with 66,000 deaths occurring during that year alone. Consequently, AIDS will continue to be one of the leading causes of mortality worldwide, necessitating an even more urgent need to control this disease through intensive targeted behavioral and educational programs. © 1990 American College of Emergency Physicians.