The oral transmission of malaria

Transmission of malaria through the oral route is analyzed looking at the evolutionary origin of Apicomplexa, Coccidia, Haemosporidia, and Plasmodium parasites. Discussion is done on the two ways of oral transmission proposed: by ingesting the meat of an infected animal, or by ingestion of the infective form of a coccidian. This discussion is linked to experimental observations to sustain a theory that consider that the original coccidian from which Plasmodium evolved is an Isospora that did not disappear in the process of speciation and, it is still with us forming part of the cycle of a parasite that behave like plasmodium and/or coccidian, depending on the host they infect. The stage of the parasite that make connection between Plasmodium and coccidian, may be the sporozoite, although merozoites may be involved in infections transferred by blood forms.