reporter and barnyjr were among the readers alerting us to the discovery of a new strain of the HIV virus, found in a woman from the west central African nation of Cameroon. "It differs from the three known strains of human immunodeficiency virus and appears to be closely related to a form of simian virus recently discovered in wild gorillas, researchers report in Monday's edition of the journal Nature Medicine. ... The most likely explanation for the new find is gorilla-to-human transmission, Plantier's team said. But... they cannot rule out the possibility that the new strain started in chimpanzees and moved into gorillas and then humans, or moved directly from chimpanzees to both gorillas and humans. ... Researchers said it could be circulating unnoticed in Cameroon or elsewhere. The virus's rapid replication indicates that it is adapted to human cells, the researchers reported."