AIDS virus traced back 100 years

The AIDS virus has been circulating among people for about 100 years, decades longer than scientists had thought, a new study suggests.

Genetic analysis pushes the estimated origin of HIV back to between 1884 and 1924, with a more focused estimate at 1908.

Previously, scientists had estimated the origin at around 1930. AIDS wasn't recognized formally until 1981 when it got the attention of public health officials in the United States.