HIV is believed to have crossed over from chimpanzees to humans in Kinshasa, the Democratic Republic of the Congo in 1920.
In 1981 in Los Angeles, a rare lung infection called Pneumocystis, carinii pneumonia (PCP) was diagnosed in five young, previously healthy gay men. Around this time there were also reports of groups of men in New York and California being diagnosed with an aggressive cancer called Kaposi’s Sarcoma. Finally in September of 1982, the CDC first used the term acquired immune deficiency syndrome (AIDS), when describing the mystery disease. The first AIDS clinic was opened in San Francisco that same year.
In 1984, Dr. Robert Gallo and his colleagues at the National Cancer Institute found the human immunodeficiency virus (HIV) as distinct from AIDS. In 1989, there were over 100,000 AIDS cases reported in America, and by 1994, AIDS had become the leading cause of death among Americans 25-44 years old. In 2014, the UNAIDS launched their 90-90-90 targets, aiming for 90% of people living with HIV to be diagnosed, 90% to be accessing antiretroviral treatment, and 90% to achieve viral suppression by 2020.