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.