The global AIDS epidemic originated in chimpanzees living in southeastern Cameroon, a viral analysis confirms.
An international team of scientists analyzed 599 fecal specimens from 10 forest sites in Cameroon and found evidence of simian immunodeficiency virus (SIV), the direct precursor of the AIDS virus, HIV-1.
In 1999, Beatrice Hahn of the University of Alabama at Birmingham detected SIV in caged chimpanzees from western Africa (SN: 2/6/99, p. 84) but didn’t pinpoint the virus’ wild habitat. Her group’s new study, which will be published in the July 28 Science, finally does that.
“We said west-central Africa, but that’s pretty big,” says Hahn. Her group has since located the cradle of the pandemic strain of HIV-1, which causes more than 99 percent of AIDS cases.
Scientists propose that a hunter contracted the virus and carried it out of the area about 70 years ago. The virus probably made its way into urban Kinshasa via the Sangha River, a trade route into the Congo basin, before stretching abroad.
Though SIV doesn’t seem to harm apes, says Hahn, studying the virus in wild chimps might explain why the pandemic strain of HIV-1 is spreading in people.