THE origins of a less virulent form of HIV, called HIV-2, have finally been confirmed.
杏吧原创s think the main cause of AIDS, HIV-1, crossed over to humans from African chimpanzees sometime after 1700, and mutated into the current human form around 1930. But they have been less sure about the origins of HIV-2, which now infects about 1 per cent of the population of West Africa.
Anne-Mieke Vandamme from the Catholic University of Leuven (KUL) in Belgium and her team compared HIV-2 to a similar virus found in sooty mangabeys, a monkey thought to be the virus鈥� original host.
Advertisement
An analysis of the genetic differences between them indicates that two strains of HIV-2 crossed from mangabeys into humans during the first half of the 20th century. HIV-2 A mutated into its current form around 1940, and HIV-2 B around 1945. Mangabeys became extinct in that part of Africa in the 1950s (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0936469100).