Scientists track HIV origins to chimpanzees in remote Cameroon jungle

RESEARCHERS have discovered a “missing link” in the search for the origin of HIV, it emerged yesterday.

Scientists from theUniversities of Nottingham, Montpellier and Alabama have tracked the source of the killer virus to a colony of wild-living chimpanzees in southern Cameroon, and believe the area is where humans first picked up the strain.

The findings of the 10-year study to locate the source of HIV provide a crucial link between Simian Immunodeficiency Virus (SIVcpz), a virus similar to HIV that is well-known to affect chimpanzees, and the cause of human AIDS.

In collaboration with a similar project being undertaken in Cameroon, researchers analysed ape faecal samples collected from the forest floor in jungle regions of the country.

In some communities they detected SIVcpz specific antibodies and viral genetic information in as many as 35% of chimpanzees.

The scientists then went on to determine the genetic sequences of the chimpanzee viruses, evolutionary analysis of which showed an extremely close genetic relationship between some of the new chimpanzee virus samples and strains of HIV-1.

Chimpanzees in the south-east of the country were found to have a virus most similar to the form of HIV-1 that has spread to humans throughout the world. Paul Sharp, Professor of Genetics at the University of Nottingham, said the findings are the most significant yet in the hunt for the source of HIV.

Prof Sharp said: “Particularly when you consider that HIV-1 probably originated more than 75 years ago, it is most unlikely that there are any viruses out there that will prove to be more closely related to the human virus.

“Thus, the initial jump of a virus from a chimpanzee to a human probably occurred in that region.”

It is hoped that further study will discover why, despite the close genetic similarity of chimps and humans, SIVcpz does not cause any AIDS-like illness in chimpanzees.

“We’re currently working to understand which genetic differences between SIVcpz and HIV-1 evolved as a response to the species jump,” Prof Sharp added.