Deadly Malaria Parasite Originates in Africa Rather Than in Asian Primates

Plasmodium vivax is known as the second-worst malaria parasite of humans. Previous studies have shown that Asian primates were the closest genetic relatives of the parasite that has put 2.5 billion people at risk. The University of Pennsylvania has conducted a study that reveals otherwise.

The parasite accounts for a majority of malaria cases outside of Africa, which are estimated to be between 80-100 million annually, according to the Broad Institute. The malaria disease as a whole is believed to affect 250 million people annually, while contributing to nearly one million deaths in 109 countries. Despite the immediate dangers that this parasite poses, many scientists believe that it is still underestimated.

The Perelman School of Medicine at the University of Pennsylvania, among other contributors, found that central African apes are infected with parasites that are genetically identical to human plasmodium vivax. This discovery negates the previous belief that the parasite originated in Asia, which is where the most humans are affected.

The researchers tested over 5,000 African ape fecal samples. They discovered Plasmodium vivax sequences in chimpanzees as well as western and eastern gorillas; in fact, the parasite was endemic in central African gorillas and chimps. The study found a high prevalence of plasmodium vivax among wild-living apes in the region, implying the existence of a natural reservoir of the parasite in Africa.

Beatrice Hahn, M.D., and George Shaw, M.D., Ph.D., are both professors of Medicine and Microbiology at Penn and also lead researchers of the study. Hahn believes that this recent discovery has changed the course of current research regarding plasmodium vivax.

"Our finding that wild-living apes in central Africa show widespread infection with diverse strains of P. vivax provides new insight into the evolutionary history of human P. vivax and resolves the paradox that a mutation conferring resistance to P. vivax occurs with high frequency in the very region where this parasite is absent in humans," said Hahn in this EurekAlert! article.

The researcher's next goal is to compare molecular and biological properties of human and ape parasites in order to find vulnerabilities that are exploited to combat malaria. To read more about the UPenn study, visit this EurekAlert! article.