READ MORE: Pandemics That Changed History: A Timeline The AIDS Epidemic Arises

International travel from the United States helped the virus spread across the rest of the globe. The virus then moved from the Caribbean to New York City around 1970 and then to San Francisco later in the decade.

In the 1960s, HIV spread from Africa to Haiti and the Caribbean when Haitian professionals in the colonial Democratic Republic of Congo returned home. The virus spread may have spread from Kinshasa along infrastructure routes (roads, railways, and rivers) via migrants and the sex trade. Researchers believe the first transmission of SIV to HIV in humans that then led to the global pandemic occurred in 1920 in Kinshasa, the capital and largest city in the Democratic Republic of Congo. SIVcpz likely jumped to humans when hunters in Africa ate infected chimps, or the chimps’ infected blood got into the cuts or wounds of hunters. These two strains likely combined to form SIVcpz, which can spread between chimpanzees and humans. Chimps, the scientist later discovered, hunt and eat two smaller species of monkeys-red-capped mangabeys and greater spot-nosed monkeys-that carry and infect the chimps with two strains of SIV. In 1999, researchers identified a strain of chimpanzee SIV called SIVcpz, which was nearly identical to HIV. Scientists have traced the origin of HIV back to chimpanzees and simian immunodeficiency virus (SIV), an HIV-like virus that attacks the immune system of monkeys and apes. And a study in 2019 in the medical journal, Lancet, showed that an anti-viral treatment effectively halted the spread of HIV. Though there is no cure for HIV or AIDS, a person with HIV who receives treatment early can live nearly as long as someone without the virus. A person with AIDS is very vulnerable to cancer and to life-threatening infections, such as pneumonia. Over time, HIV can destroy so many CD4 cells that the body can’t fight infections and diseases, eventually leading to the most severe form of an HIV infection: acquired immunodeficiency syndrome, or AIDS. Historically, HIV has most often been spread through unprotected sex, the sharing of needles for drug use, and through birth. The virus is transmitted through bodily fluids such as blood, semen, vaginal fluids, anal fluids, and breast milk. The human immunodeficiency virus, or HIV, is a virus that attacks the immune system, specifically CD4 cells (or T cells).

Red ribbon aids