Malaria parasite in red blood cell. Light micrograph of a red blood cell (erythrocyte) infected with a Plasmodim vivax protozoan. This parasite causes recurring malaria in humans. This is the schizont stage of the protozoan's life cycle, during which it reproduces asexually. The erythrocyte, which is larger than the uninfected cells, is showing characteristic Shuffner's dots (red). P. vivax is transmitted to humans via the bite of an infected female Anopheles sp. mosquito. Symptoms include fever and headache, which can proceed to coma and death. Wright's stain.