HIV ancestor traced back 32,000 years

A new study says the virus has been in monkeys and apes for much longer than previously thought.

Humans have been exposed to a form of HIV for millennia, according to a new study. Scientists tested monkeys on the island of Bioko, 30 km off the West Coast of Africa, and found that four species there were infected with SIV, the simian immunodeficiency virus that HIV is derived from. Because the island separated from the African mainland 10,000 years ago, researchers concluded the virus is at least that old, and probably first came into existence 32,000 years ago. Our ancestors were likely exposed to the virus countless times when they butchered monkeys and apes for food. The virus has crossed from simians to humans at least five times, but only became widespread in the 1980s.