in full acquired immunodeficiency syndrome
Fatal transmissible disorder caused by HIV .
AIDS, the last stage of HIV infection, is defined by the appearance of potentially lethal opportunistic infections. The first AIDS cases were identified in 1981, HIV was isolated in 1983, and blood tests were developed by 1985. In 2002 approximately 40,000,000 people worldwide were living with HIV, and more than 25,000,000 had died of AIDS. In the U.S. some 2,000,000 people had been infected with HIV, 800,000 had been diagnosed with AIDS, and 450,000 had died. Sub-Saharan Africa remains the focus of infection, but the number of cases in South and Southeast Asia and elsewhere continues to mount at an alarming rate as well. An initial acute illness usually resolves within weeks. Infected persons then generally have few or no symptoms for about 10 years. As the immune system deteriorates, they develop diseases such as Pneumocystis carinii pneumonia , cytomegalovirus (CMV) , lymphoma , or Kaposi sarcoma .