The origin of HIV has been found in wild chimpanzees living in southern Cameroon, researchers report. A virus called SIVcpz (Simian Immunodeficiency Virus from chimps) was thought to be the source, but had only been found in a few captive animals. Now, an international team of scientists has identified a natural reservoir of SIVcpz in animals living in the wild. The findings are to be published in Science magazine. It is thought that people hunting chimpanzees first contracted the virus - and that cases were first seen in Kinshasa, in the Democratic Republic of Congo - the nearest urban area...