Human Immunodeficiency Virus
Human immunodeficiency virus (HIV) is a retrovirus that causes acquired immunodeficiency syndrome (AIDS). AIDS is one of the most devastating epidemics ever recorded in the world. AIDS was first recognized in Los Angeles in 1981, when five cases of Pneumocystis carinii (now called Pneumocystis jir-ovecii) pneumonia in homosexual men and drug addicts werereported. The causative agent of AIDS was first reported by Luc Montagnier and colleagues from the Pasteur Institute, Paris, in 1983. They isolated a retrovirus from a West Asian patient with persistent generalized lymphadenopathy and named it
Lymphadenopathy-associated virus (LAV). In 1984, Robert Galloand colleagues from the National Institute of Health, USA, reported isolation of a retrovirus from patient with AIDS and called it human T cell lymphotropic virus-III (HTLV-III).
The International Committee on Virus Nomenclature in 1986 gave the name human immunodeficiency virus, or HIV, for the same virus. HIV-1 is first isolated virus from the cases of AIDS, and HIV-2 has been isolated from some case of AIDS from West Africa.
HIV is a Lentivirus, a sub family of Lentiviridae in the family retrovirus. This family includes the viruses known for (i) poor host immune responses, (ii) latency, (iii) persistent viremia, and (iv) infection of the central nervous system. HIV, like other ret-roviruses, are enveloped RNA viruses, characteristically pos-sessing an RNA-dependent DNA polymerase called reverse transcriptase.