“The conventional wisdom on malaria is that this is a disease that has been in humans since the dawn of humanity,” said infectious disease expert Nathan Wolfe of Stanford University, who co-authored the paper published Monday in the Proceedings of the National Academy of Sciences. “In fact, what we found was really quite surprising to us: There is a tremendous diversity of these parasites in chimpanzees, and it’s a diversity that completely encompasses a much more limited diversity in human malaria.”
“There’s only one way to interpret that finding,” Wolfe said. “Namely, that this is a chimpanzee parasite that had jumped over to human populations.”
According to Ed Yong, plasmodium protein EBA-175 binds to GYPA on the surface of the red blood cells. A gene, CMAH, crippled in humans and active in chimps renders chimps susceptible to P. reichinowi but not humans. However, a different EBA-175, possibly unique to P.falciparum can infect human RBC. This may explain why humans are susceptible to P. falciparum.
Such theories of differential evolutionary trajectories of the same gene in chimp and human is not new rendering humans susceptible to a particular disease is not new. Scientists working with trim5alpha have suggested the same for HIV. Interestingly for Malaria though, there is another species of plasmodium, P. vivax, that according to the malarial species tree, is in a completely different branch and infects humans, although without being as detrimental as its counterpart evolved from the chimps.
So, it is very important to understand whether all human malarial parasites use the same pathway to infect RBCs. May be it is already known and I am unaware about it…anyone knows?