Researchers published their findings in the journal Nature. They have found through genetic analysis that the virus likely originated in humans sometime between 1884 and 1924, with a more focused estimate at 1908.

The new findings were discovered in samples of patients in Africa taken in 1959 and 1960. Samples were positive for the virus, and the mutations of the virus allowed scientists to work backward, figuring how long it would've taken the virus to morph into the strain it was in at that time.

The New York Times reported that the virus was transferred from chimpanzees to humans in Africa, most likely when Chimpanzees were being butchered. Researchers say it is likely the disease was not transferred en masse until infected people began living in cities, where transmission was more likely do to things like prostitution.

Until now the virus was thought to have originated around 1930.