Circumsporozoite protein gene from Plasmodium brasilianum. Animal reservoirs for human malaria parasites?

We describe here the sequence of the circumsporozoite protein gene of the monkey malaria parasite Plasmodium brasilianum and show that the immunodominant repeat domain is the same as that of the human malaria parasite, Plasmodium malariae. The immunodominant epitope on the surface of sporozoites of a third species of human malaria parasite has, therefore, been identified. This genetic based data and the biological similarities between P. brasilianum and P. malariae support their putative zoonotic/anthroponotic relationship. We also show that an ape malaria parasite, Plasmodium reichenowi, and the human malaria parasite, Plasmodium falciparum, have a similar relationship. The implications of these observations are discussed with respect to vaccine development.