Today’s Guardian (and just about every news source on the planet) carried the story that scientists searching for the origin of HIV may have tracked its source to chimpanzees living in southern Cameroon.. Their findings may well provide the link between HIV, and the simian immunodeficiency virus (SIV), a similar virus that infects monkeys and chimpanzees.
Cameroon has two subspecies of chimpanzee, separated by the Sanaga river. North of the river, the chimpanzees are free of SIV, but it was present in colonies immediately on the southern side. Further south tests on chimpanzee faeces here revealed an SIV strikingly similar to the HIV that causes Aids in humans. In some communities they detected SIV specific antibodies and viral genetic information in as many as 35% of chimps.
Researchers have various theories on how the virus jumped to humans but the most widely held view is thatsome times before the 1930s hunters became infected when they caught and butchered infected chimps. Trade along river routes could then have spread the virus, which slowly built up in the human population.
For scientists this may well prove to be an important piece in the HIV puzzle even if many unanswered questions remain. It unlikely, however, to satisfy those who choose to believe less prosaic theories. Those who subscribe, for example, to the ludicrous belief that HIV was created by the USA to kill off africans and homosexuals will probably continue to wallow in this delusion.