Human malaria 'came from gorillas thousands of years ago': Discovery raises hopes of vaccine for disease

Malaria first passed to humans from gorillas thousands of years ago, according to new research.
The parasite that causes the deadly infection has been traced back to the animals who passed it on to us in a single transmission.
The latest discovery could aid the development of a vaccine for malaria, which kills about 1.5 million each year and sickens 500 million more.

It also furthers understanding of how infectious diseases such as HIV, SARS, and avian and swine flu can be transmitted to humans from animals.
Scientists analysed 2,500 primate faeces samples collected in Africa and found DNA evidence of Plasmodium falciparum, the parasite that causes malaria in humans, in up to half of those produced by gorillas.
P. falciparum is the most deadly type of malaria infection. It is most common in Africa, south of the Sahara, where the World Health Organisation says it accounts for a large part of the extremely high mortality in the region.

Dr Weimin Liu, of the University of Alabama, and colleagues said their findings show P. falciparum is of gorilla origin rather than chimpanzee, bonobo or ancient human as previously thought.
Until recently, the closest known relative of P. falciparum was a chimpanzee parasite Plasmodium reichenowi which was assumed to have diverged from its human counterpart at the same time as the ancestors of chimpanzees and humans more than five million years ago.
Within the past year other closely related Plasmodium strains have been detected in chimpanzees, western gorillas and bonobos, raising the possibility that P. falciparum in humans could have arisen as a consequence of cross-species transmission from one or more of these apes.
But the researchers said their studies were limited by an analysis of only few apes, many of which were captive and living in close proximity to humans.
Dr Edward Holmes, of Pennsylvania State University, who reviewed the study, said it is impossible to say exactly when malaria was passed on to humans. But he added: 'When it comes to disease, chimpanzees get a bad press.
'We have known for more than a decade that chimpanzees are the source of HIV-1, the major cause of AIDS, and probably acquired the virus themselves by eating infected monkeys.'
'More recently, chimpanzees have been proposed as the reservoir of human Plasmodium falciparum, a parasite that causes the most severe type of malaria.
'However the research shows that another of our great-ape cousins, the gorilla, is in fact a more likely progenitor species for this form of human malaria.'