Deadly human malaria parasite may have come out of Africa
Researchers have claimed to have linked origin of deadly human malaria parasite to primates to Africa, and not Asia, as once believed.
Until recently, the closest genetic relatives of human P. vivax were found only in Asian macaques, leading researchers to believe that P. vivax originated in Asia.
The study, led by researchers from the Perelman School of Medicine at the University of Pennsylvania, found that wild-living apes in central Africa are widely infected with parasites that, genetically, are nearly identical to human P. vivax.
This finding solves vexing questions about P. vivax infection: how a mutation conferring resistance to P. vivax occurs at high frequency in the very region where this parasite seems absent and how travelers returning from regions where almost all humans lack the receptor for P. vivax can be infected with this parasite.
Ape P. vivax infects both gorillas and chimpanzees, unlike the ape precursor of P. falciparum, the deadliest human malaria parasite, which only infects gorillas.
The origin of P. falciparum in gorillas was discovered several years ago by the same international group of investigators.
The team continued its widespread screen of malaria parasite DNA in wild-living primates, and noted that P. vivax was also endemic in gorillas and chimpanzees in central Africa.
To examine the evolutionary relationships between ape and human parasites, the team generated parasite DNA sequences from wild and sanctuary apes, as well as from a global sampling of human P. vivax infections.
They constructed a family tree of the sequences and found that ape and human parasites were very closely related. But ape parasites were more diverse than the human parasites and did not group according to their host species. In contrast, the human parasites formed a single lineage that fell within the branches of ape parasite sequences.
The study has been published in the journal Nature Communications.
(Posted on 22-02-2014)