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What is HIV infection and AIDS?
Last reviewed: 04.07.2025
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HIV infection is a long-term infectious disease caused by the human immunodeficiency virus (HIV), which affects cells of the immune, nervous and other systems and organs of a person. With HIV infection, the immune system is damaged, leading to the development of acquired immunodeficiency syndrome (AIDS).
HIV infection was first identified in 1981, when the Centers for Disease Control and Prevention (CDC) reported 5 cases of Pneumocystis pneumonia and 28 cases of Kaposi's sarcoma in previously healthy homosexuals. Immunological testing of these patients revealed a sharp decrease in the level of CD4 lymphocytes. The diagnosis of Acquired Immunodeficiency Syndrome (AIDS) was first formulated.
In subsequent publications, descriptions of AIDS in heterosexual men and women appeared. The number of women did not exceed 5% of the total number of patients, but these data showed that the homosexual route of transmission could not be considered the only one.
Descriptions of cases of AIDS infection in hemophiliacs who received repeated intravenous infusions of hemoconcentrates indicated the possibility of not only sexual but also parenteral routes of infection.
The infection with AIDS through transfusion of whole blood and its preparations from clinically healthy donors was direct confirmation of the existence of a latent stage of the infectious process.
Of significant epidemiological significance were the data on the detection of clinical signs of AIDS in intravenous drug addicts, who later became the main high-risk group for HIV infection.
The human immunodeficiency virus was isolated in 1983 by Professor Luc Montagnier's group (Pasteur Institute, France) from the lymph node of an AIDS patient. That same year in the USA, Professor Robert Gallo's group (National Cancer Institute, USA) isolated the virus from peripheral blood lymphocytes of AIDS patients. Both viruses turned out to be identical and in 1987 the WHO adopted a single name - "human immunodeficiency virus" (HIV, English abbreviation - HIV).
In 1996, at the AIDS Congress in Vancouver, the results of using highly active antiretoviral therapy with the prescription of three drugs: two reverse transcriptase inhibitors and one protease inhibitor (HAART, Highly Active Antiretoviral Therapy) were reported. More than 2/3 of AIDS patients on HAART were discharged from the hospital and were able to return to work.
An important aspect of the problem is the analysis of the background of the HIV pandemic. Thus, the results of the analysis of the archives of medical records showed that in the period from 1979 to 1982, 509 patients with signs of AIDS were identified, of whom 209 died. Especially many of these patients were in the regions of Central Africa, where, judging by the archival materials, AIDS patients had been observed since 1962.
It is assumed that the ancestral home of HIV was the region of tropical aquatic Africa, corresponding to the habitat of green monkeys, in which the existence of a close virus, Simian Immunodeficiency Virus SIV (SIV-monkey immunodeficiency virus), has been proven. Gradually, the virus adapted to the conditions of existence in the human body, and SIV was transformed into HIV. The zoonotic infection turned into an anthroponotic one, which first received sporadic, epidemic and then pandemic spread.