Researchers have discovered that the most common form of human malaria—Plasmodium falciparum—may have originated in western lowland gorillas. The closest genetic match between malaria that infects humans and one that infects gorillas has been found.
The result, which contradicts previous studies that point to chimpanzees as the potential reservoir of malignant malaria, has been published in the latest issue of science journal Nature. This research was led by Dr Beatrice Hahn and colleagues at University of Alabama at Birmingham. The authors also include Dave B Morgan and Crickette M Sanz of the Wildlife Conservation Society (WCS) and Lincoln Park Zoo
According to a statement issued by WCS, the researchers used non-invasive methods to genetically screen wild populations of gorillas, chimpanzees, and bonobos across Africa by collecting more than 2,700 fecal samples from more than 50 sites, including the Goualougo Triangle and Nouabalé-Ndoki National Park in northern Republic of Congo, two protected areas which the Wildlife Conservation Society helped to establish. Fecal samples from great apes in this region had the highest prevalence of Plasmodium organisms, indicating that this area is important for studies focusing on malaria in great apes.
“Protected areas that were established in large part to safeguard globally important populations of gorillas and chimpanzees are now yielding another important benefit,” said Dr Morgan. “By conserving these great ape populations, we also preserve the ability to gain valuable insights into the origin of pathogenic threats that impact human populations.”
The research team extracted genetic material from the fecal samples. A new technique allowed researchers to avoid the possibility of the recombination of sequences that have confounded earlier studies. The findings revealed a strain of Plasmodium in gorillas that was a close match to malaria organisms that infect humans, suggesting that the pathogen originated in western gorilla populations and not chimpanzees as indicated in previous studies. Researchers found that more than half of all apes in some sites were infected.
Malaria is a disease caused by the bite of the Anopheles mosquito which introduces the parasite belonging to the Plasmodium genus. Five types are known to infect humans, and one species———annually causes millions of malarial cases, with more than one million deaths every year.
