Epidemiology of HIV Infection and AIDS in the United States

Abstract

HIV-1 disease has been recognized as a distinct clinical entity for fewer than 10 years. Yet during that time, the virus has spread around the world and affects people of virtually all ages, genders, sexual behaviors, and geographic regions. In the United States, there have been more than 140,000 individuals diagnosed with AIDS, the clinical end stage of HIV-1 disease, and it is projected that AIDS incidence will accelerate through at least 1993. In the early years of the infection epidemic in the United States, the virus spread rapidly and insidiously, predominantly among homosexual men, intravenous drug users, people with hemophilia, and recipients of infected blood products. Since then, the epidemic has been propagated concurrently with epidemics of drug use (intravenous and noninjectable) and sexually transmitted diseases such as syphilis. Since its beginning, HIV-1 has disproportionately affected members of racial and ethnic minorities, particularly in large cities, where transmission takes place sexually, parenterally, and perinatally. The epidemic of HIV-1 has spread outside of traditional urban epicenters and is more significantly affecting adolescents, women, and heterosexuals. There is a great need for renewed and refocused infection-prevention efforts. Projections of resource and medical service needs should be based on up-to-date and accurate assessments of infection epidemic parameters, including infection prevalence, incidence, and acceleration (changes in epidemic velocity over time) rates.