AIDS was first reported June 5, 1981, when the U. S. Centers for Disease Control (CDC) recorded a cluster of Pneumocystis cariniipneumonia (now still classified as PCP but known to be caused by Pneumocystis jirovecii) in five homosexual men in Los Angeles. In the beginning, the CDC did not have an official name for the disease, often referring to it by way of the diseases that were associated with it, for example, lymphadenopathy, the disease after which the discoverers of HIV originally named the virus. They also used Kaposi's Sarcoma and Opportunistic Infections, the name by which a task force had been set up in 1981.
In the general press, the term GRID, which stood for gay-related immune deficiency, had been coined. The CDC, in search of a name, and looking at the infected communities coined “the 4H disease, ” as it seemed to single out Haitians, homosexuals, hemophiliacs, and heroin users. However, after determining that AIDS was not isolated to the gay community, the term GRID became misleading and AIDS was introduced at a meeting in July 1982. By September 1982 the CDC started using the name AIDS, and properly defined the illness.
The earliest known positive identification of the HIV-1 virus comes from the Congo in 1959 and 1960 though genetic studies indicate that it passed into the human population from chimpanzees around fifty years earlier. A 2007 study states that a strain of HIV-1 probably moved from Africa to Haiti and then entered the United States around 1969.
HIV descends from the related simian immunodeficiency virus (SIV), which infects apes and monkeys in Africa. There is evidence that humans who participate in bushmeat activities, either as hunters or as bushmeat vendors, commonly acquire SIV. However, only a few of these infections were able to cause epidemics in humans, and all did so in the late 19th—early 20th century. To explain why HIV became epidemic only by that time, there are several theories, each invoking specific driving factors that may have promoted SIV adaptation to humans, or initial spread: social changes following colonialism, rapid transmission of SIV through unsafe or unsterile injections (that is, injections in which the needle is reused without being sterilised), colonial abuses and unsafe smallpox vaccinations or injections, or prostitution and the concomitant high frequency of genital ulcer diseases (such as syphilis) in nascent colonial cities.
One of the first high profile victims of AIDS was the American Rock Hudson, a gay actor who had been married and divorced earlier in life, who died on 2 October 1985 having announced that he was suffering from the virus on 25 July that year. It had been diagnosed during 1984. A notable British casualty of AIDS that year was Nicholas Eden, a gay Member of Parliament and son of the late prime minister Anthony Eden. The virus claimed perhaps its most famous victim yet on 24 November 1991, when British rock star Freddie Mercury, lead singer of the band Queen, died from an AIDS related illness having only announced that he was suffering from the illness the previous day. However he had been diagnosed as HIV positive during 1987. One of the first high profile heterosexual victims of the virus was Arthur Ashe, the American tennis player. He was diagnosed as HIV positive on 31 August 1988, having contracted the virus from blood transfusions during heart surgery earlier in the 1980s. Further tests within 24 hours of the initial diagnosis revealed that Ashe had AIDS, but he did not tell the public about his diagnosis until April 1992. He died, aged 49, as a result of the AIDS virus on 6 February 1993.
A more controversial theory known as the OPV AIDS hypothesis suggests that the AIDS epidemic was inadvertently started in the late 1950s in the Belgian Congo by Hilary Koprowski's research into a poliomyelitis vaccine.