1985: Forty years ago, the world opened its eyes to AIDS. History of the early years of the HIV epidemic

At the end of 1980, Michael Gottlieb, a researcher at the University of California, was conducting a clinical study on deficiencies of the immune system when he heard of the case of a young man with a rare form of pneumonia due to Pneumocystis carinii (now known as Pneumocystis jirovecii), a protozoon that usually affects only people with a weakened immune system [1]. In the following months, Gottlieb discovered further cases of patients with Pneumocystis carinii pneumonia, oral candidiasis and a very low level of T lymphocytes. All were male and active homosexuals [2]. In reality the infection had already manifested itself in previous years but had always been mistaken for something else [3]. HIV probably originated from a virus found in chimpanzees and began infecting humans in the first half of the 20th century. It probably emerged when members of the Bantu tribe, who lived in the forests of central Africa, consumed chimpanzee meat infected with a virus called simian immunodeficiency virus (SIV). This may have caused a so-called spillover from chimpanzees to humans [4, 5].