HIV may date back to the 1930s

From San Francisco, at the 7th Conference on Retroviruses and Opportunistic Infections

The AIDS epidemic’s devastation first became apparent in the 1980s. Now, using one of the world’s most powerful computers, researchers estimate that the disease began spreading among people as long ago as 1930.

Because the genetic material of the virus that causes AIDS mutates frequently, there are now dozens of HIV varieties. Bette T. Korber of Los Alamos (N.M.) National Laboratory and her colleagues used genetic sequences of most known varieties to construct the fullest family tree of HIV to date.

The two main branches of the AIDS virus family, known as HIV-1 and HIV-2, probably infected human populations several times before spreading to epidemic proportions, Korber says.

Confirming its accuracy, the model correctly placed in the family tree the genetic sequences of the earliest known HIV, found in a 1959 blood sample, and an HIV strain that appeared in Thailand in 1987, she says.

“There’s been a lot of interest in the speculation that the HIV-AIDS epidemic might have its origin in the African polio vaccinations of the late 1950s,” Korber says. “While our results don’t disprove this theory, they make it very unlikely.”