Plasmodium ovale. Plasmodium ovale is a species of parasitic protozoa that causes tertian malaria in humans. It is one of several species of Plasmodium parasites that infect humans including Plasmodium falciparum and Plasmodium vivax which are responsible for most malarial infection.
After being bitten by a mosquito carrying malaria, a person will not notice symptoms for one week to one month. During this time, malaria parasites multiply in a person's liver before invading red blood cells in the bloodstream. Once inside a person's red blood cells, the parasites continue to multiply and spread the infection.
Malaria is caused by single-celled organisms, called protozoans, of the genus Plasmodium. Different forms of malaria are caused by different species of Plasmodium. The most severe and deadly form is caused by P. falciparum, which is responsible for 90% of the global deaths from malaria, the majority of these in Africa, and mostly in young children.