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

In developing trophozoites of P. knowlesi, band forms may appear that are similar in appearance to P. malariae.  As the vacuole is lost during maturation of the trophozoite stage, the parasite becomes smaller and more compact.  The pigment appears as dark grains and the red nucleus increases in size.  Stippling appears, often referred to as 'Sinton and Mulligan's' stippling, as it is not of the Schüffner type.

Plasmodium knowlesi trophozoites

A

A: Trophozoites of P. knowlesi.  Figs. 11-12: Developing trophozoites; Figs 13-15: Mature trophozoites.
Illustrations from: Coatney GR, Collins WE, Warren M, Contacos PG. The Primate Malarias. Bethesda: U.S. Department of Health, Education and Welfare; 1971.

Plasmodium knowlesi trophozoites in thin blood smear Plasmodium knowlesi trophozoites in thin blood smear
B C

B: Band-form trophozoite of P. knowlesi in a blood smear from a human patient that traveled to the Philippines.  Image courtesy of the Wadsworth Center, New York State Department of Health.
C: Band-form (upper) and ring-form (lower) trophozoites of P. knowlesi, from the same specimen as Figure B.

 
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