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

Plasmodium malariae: Ring Stage Parasites

P. malariae ring stage

Fig. 1: Normal red cell; Figs. 2-5: Rings.
Illustrations from: Coatney GR, Collins WE, Warren M, Contacos PG. The Primate Malarias. Bethesda: U.S. Department of Health, Education and Welfare; 1971.

Smears from patients:

Plasmodium malariae rings have sturdy cytoplasm and a large chromatin dot.  The red blood cells (RBCs) are normal to smaller than normal (3/4×) in size.

P. malariae ring - thin smear P. malariae ring - thin smear P. malariae ring - thin smear
A B C

A, B, C: Ring forms in thin blood smears.

P. malariae rings (lower right) - thick smear
D

D: A thick blood smear showing two rings (lower right) and a gametocyte.
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