[Last Modified: ]

April 2007
Answer to Case 202
This was a case of malaria caused by Plasmodium ovale.  Many of the images depicted a classic presentation of P. ovale morphology; diagnostic features included:

• enlarged infected RBCs (1 1/4 to 1 1/2×).
• the presence of Schϋffner's dots in the infected RBCs.
• elongated and fimbriated RBCs.
• the presence of multiple stages of Plasmodium, including:
  • compact trophozoites with sturdy cytoplasm (Figure D)
  • round to oval gametocytes that almost filled the RBCs (Figures A, C, and F)
  • immature schizonts (Figures B and E).  Immature schizonts are often not helpful for making a diagnosis because the merozoites are not fully developed and therefore cannot be counted.  The size of the RBC can still be taken into consideration.

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