Skip to Content
Medical Term:

Plasmodium vivax


a protozoan species that is the most common malarial parasite of humans (except in West Africa, where the form of the Duffy antigen [FyFy] protects most of the resident populations, which has permitted Plasmodium ovale to replace Plasmodium vivax); the early trophozoite is irregular and ameboid in shape, one quarter to one third the size of an erythrocyte, and contains several fine granules; the schizont is irregular in shape, fills the enlarged erythrocyte, and contains numerous yellow-brown pigment granules; affected erythrocytes are pale, enlarged, and contain Schüffner dots in the later stages of growth; characteristically causes bouts of fever fairly regularly at 48-hour intervals, but multiple infection, causing irregular fever patterns, is common.

Synonym(s): tertian parasite

© Copyright 2017 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.