Case #205 – June, 2007

A 30-year-old man from Sudan had fever and chills. He was also mildly jaundiced. He went to his physician who ordered a blood smear examination. Smears were made and stained with Leishman’s stain. Figures A-E were captured from the thin smears. What is your diagnosis? Based on what criteria?

Figure A

Figure B

Figure C

Figure D

Figure E

This was a case of malaria caused by Plasmodium vivax. Diagnostic features included:

amoeboid trophozoites (Figure A). The infected red blood cells (RBCs) were enlarged 1.5×, and in one, there was a hint of Schϋffner’s stippling.
a slightly-enlarged gametocyte (Figure B).
a schizont with approximately 15 or 16 merozoites (Figure C).
microgametes, a result of exflaggelation of male gametocytes (microgametocytes). This can happen when the blood sits for a while at room temperature before the smears are made. They should not be mistaken for trypanosomes, which are much broader and have a nucleus and a kinetoplast.