 SIV jumped from primates to humans several times, although the primary strain of HIV responsible for the global pandemic, HIV-1 group M, is traceable to the region surrounding Kinshasha, likely having initially crossed from chimpanzees around 1920.From there, it spread to the Caribbean around 1967, proceeding to establish itself in New York City and San Francisco circa 1971 and 1976, respectively.The Centers for Disease Control and Prevention (CDC) recognized unusual outbreaks of opportunistic infections among gay men in 1981, and the disease was initially referred to as Gay-related immune deficiency (GRID), although it was quickly understood to also infect heterosexuals as well.