HIV has been circulating in North America since the early 1970s, most likely arriving from Haiti via Africa, researchers reported in Nature. The genetic study effectively dispels the theory that one man, known as Patient Zero, was responsible for the AIDS epidemic in North America.

Michael Worobey, PhD, from the Department of Ecology and Evolutionary Biology, University of Arizona in Tucson, and colleagues serologically screened more than 2,000 serum samples from the 1970s and developed a highly sensitive approach for recovering viral RNA from degraded archival samples. They reported 8 coding-complete genomes from US serum samples from 1978 to 1979, which represent 8 of the 9 oldest HIV-1 group M genomes. 

“This early, full-genome ‘snapshot’ reveals that the US HIV-1 epidemic exhibited extensive genetic diversity in the 1970s but also provides strong evidence for its emergence from a pre-existing Caribbean epidemic,” the researchers stated. “Bayesian phylogenetic analyses estimate the jump to the US at around 1970 and place the ancestral US virus in New York City with 0.99 posterior probability support, strongly suggesting this was the crucial hub of early US HIV/AIDS diversification.

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“We also recovered the HIV-1 genome from the individual known as ‘Patient 0′ and found neither biological nor historical evidence that he was the primary case in the US or for subtype B as a whole,” the investigators concluded.

An accompanying editorial published in Nature stated, “Medical historians have chipped away at the pernicious story of [Gaétan] Dugas as Patient Zero for years. They have pointed out, for example, how he helped epidemiologists to trace a significant number of his sexual partners. And how the scientific advice at the time was contradictory and distrusted by people whose sexuality medics had considered a psychiatric problem until just a decade earlier.

“The latest genetic analysis completes the exoneration. The virus arrived in New York City from the Caribbean around 1970. There is nothing in the samples from Dugas that implicate him and his behavior as key to its subsequent rapid spread. In his 1982 letter, Dugas wrote that ‘my mind is finding peace again.’ RIP.”


  1. Worobey M, Watts TD, McKay RA, et al. 1970s and ‘Patient 0’ HIV-1 genomes illuminate early HIV/AIDS history in North America. Nature. 2016. doi: 10.1038/nature19827.
  2. [No authors]. How researchers cleared the name of HIV Patient Zero. Nature. 2016;538(7626):428. doi: 10.1038/538428a.