Normal red blood cell (erythrocyte) and red blood cell infected with the malaria parasite (Plasmodium falciparum, schizont stage), animated coloured scanning electron micrograph (SEM). The upper right red blood cell there is a large protrusion that is the schizont stage of the malaria parasite that is dividing and growing in the red blood cell. Malaria is caused by Plasmodium spp., protozoa. It is spread to humans by Anopheles species mosquitoes. The plasmodial parasite reproduces asexually in red blood cells significantly destroying many of them. Release of mature Plasmodium merozoites results in further infection and produces bouts of shivering fever (paroxysms) and sweating that may be fatal.