Malaria is caused by four different species: Plasmodium falciparum, P. malariae, P. ovale and P. vivax. The disease causes anemia in sufferers.
Between 300 and 500 million people a year are infected with malaria, and 1 million die a year from the disease. P. falciparum causes the most severe form of the disease, but malaria is most commonly caused by P. vivax.
The Anopheles mosquito carrying a Plasmodium species bites a human. This process introduces the sporozoites of the malarial protist into the human body. These sporozoites enter the hepatocytes, the liver cells, and multiply. The progeny of the sporozoites, called merozoites, then enter the bloodstream to infect the red blood cells. The red blood cells are then destroyed by the merozoites, thus releasing the merozoites and causing anemia.