Diagnostic Findings [Last Modified: ]
Malaria
[Plasmodium falciparum] [Plasmodium knowlesi] [Plasmodium malariae] [Plasmodium ovale] [Plasmodium vivax]
Causal Agent Life Cycle Geographic Distribution Clinical Features Laboratory Diagnosis Treatment

Developing schizonts of P. vivax are large and amoeboid.  Chromatin is arranged in two or more masses; pigment is also usually arranged in more than one mass.  Mature schizonts contain 12-24 merozoites, each of which contains a dot of chromatin and a mass of cytoplasm.  Pigment is usually organized in one or two clumps.  Like other stages, infected RBCs are usually larger than uninfected RBCs.

Plasmodium vivax schizonts

A

A: Schizonts of P. vivax in thin blood smears.  Figs. 19-21: Early schizonts; Figs. 22-23: Developing schizonts; Figs. 24-27: Nearly mature and mature schizonts.
Illustrations from: Coatney GR, Collins WE, Warren M, Contacos PG. The Primate Malarias. Bethesda: U.S. Department of Health, Education and Welfare; 1971.

Plasmodium vivax schizont in thick blood smear Plasmodium vivax schizont in thick blood smear
B C

B, C: Schizonts of P. vivax in thick blood smears.

Plasmodium vivax schizont in thin blood smear Plasmodium vivax schizont in thin blood smear
D E

D, E: Schizonts of P. vivax in thin blood smears.

Plasmodium vivax schizont in thin blood smear Ruptured schizont of Plasmodium vivax in thin blood smear
F G

F: Schizont of P. vivax in a thin blood smear.
G: Ruptured schizont of P. vivax in a thin blood smear, showing free merozoites and pigment.

 
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