Scientists say they have pinpointed the origin of the AIDS virus. It all started in southern Cameroon in West Central Africa around 1930, according to a study published online by the journal Science. The virus that started the global pandemic --- recognized 25 years ago next week --- passed from chimps to humans in that area.
The reservoir of the ancestral virus still exists among chimpanzee communities in the same area of Cameroon.
Now that scientists have uncovered HIV's origin, they're hoping to find clues to help battle the pandemic that has since infected 60 million people around the world. Among the first tasks: studying how a virus that doesn't harm chimps can infect humans and devastate their immune systems.