Africa: Gorillas Spread Malaria to Humans, Say Scientists

Gorillas are likely to have been the original source of malaria in humans, and the parasite probably jumped across the species about 5,000 years ago, say scientists, who will begin screening humans living near gorillas to see if the parasite is still moving between the populations today.

An international team of scientists working in Cameroon, Central African Republic and the Democratic Republic of Congo (DRC), has shown that the parasite Plasmodium falciparum, which causes the most dangerous form of malaria, probably made a single jump from gorillas – not bonobos or chimpanzees as previously thought.

The discovery could influence the understanding of malaria in the same way that comparisons of the biology of HIV with its equivalents in apes have given scientists greater insight into the mechanisms behind the disease.

The team, whose work is published in Nature today (23 September), collected thousands of samples of ape faeces to screen for malaria parasites.

“By studying the closest relative to human P. falciparum in gorillas, I cannot imagine that this would not give important clues as to why the human parasite is so pathogenic [disease-causing],” lead researcher Beatrice Hahn, a professor at the University of Alabama at Birmingham (UAB), United States, told SciDev.Net.

Jean-Bosco N. Ngona, co-author of the study and a scientist at the University of Kisangani, DRC, said that more work is needed to understand whether there are malaria interactions between gorillas and humans today.

“It would give you a heads-up of what there might be to come,” said Hahn. “As future eradication efforts bear fruit, you could generate a niche for a new parasite to move in.”

Nathan Wolfe, director of the Global Viral Forecasting Initiative (GVFI), said the work was a “great finding … we need to think about the possibility that some of these parasites might be entering the human population”.

Such movements could go undetected in the developing world, he said, where diagnosing the presence of the malaria parasite is done by looking at its structure and shape rather than its genes.

“It’s very likely if any of these other parasites was found in a human it would be misdiagnosed as P. falciparum,” he said.

Benjamin Kolb |24 September 2010|SciDev.Net (London)|