acquired immune deficiency syndrome (AIDS)

A disease thought to always be fatal, caused by infection with human immunodeficiency virus (HIV). Many researchers now refer to this disease as HIV disease rather than AIDS. Following infection, symptoms include fever, night sweats, and swollen lymph nodes. This brief acute phase precedes the development of antibody responses (seroconversion), which usually takes place six to 12 weeks after infection. In the interval between infection and antibody response (“window period”), the individual is infectious, but the infection is not detected on antibody tests. Following the acute phase, there are four stages of the HIV disease continuum. Stage 1 lasts from a few months to many years, during which the infected person is mostly asymptomatic but infectious. Stage 2 symptoms include a range of mild infections, weight loss, and fatigue. Stage 3, formerly called “AIDS-related complex” (ARC), symptoms may include episodic occurrences of pulmonary tuberculosis, pneumonia, Kaposi's sarcoma, persistent fever, excessive weight loss, and other symptoms. In stage 4 the diagnosis of AIDS is made. The immune system is so severely suppressed that the body cannot defend against infection. Some drugs may play a role in slowing infection or in bolstering the immune system, but there is no cure for AIDS, and the body ultimately loses the capacity to defend itself against one or more fatal infections or conditions. People with AIDS often face discrimination and need health and social services ranging from pretest and posttest counseling, through assistance in applying for insurance or social security benefits, to hospice care.