HIV and men who have sex with men

Since reports of emergence and spread of the human immunodeficiency virus (HIV) in the United States between the 1970s and 1980s, the HIV/AIDS epidemic has frequently been linked to gay, bisexual, and other men who have sex with men (MSM) by epidemiologists and medical professionals. It was first noticed after doctors discovered clusters of Kaposi's sarcoma and pneumocystis pneumonia in homosexual men in Los Angeles, New York City, and San Francisco in 1981.

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