Answer to Case 97
This was a case of malaria caused by Plasmodium vivax.  Diagnostic features observed were:

• Thick smear (Figure A): Many parasites seen (rings, trophozoites, early schizonts, and gametocytes).  The presence of many nuclei in the schizont was suggestive of P. vivax or P. falciparum; the morphology of the gametocytes helped rule out the latter.
• Thin smear:
  • Figure B shows a large ring.
  • Figure C shows an ameboid trophozoite in an enlarged red blood cell (1¼ to 1½× normal size) with Schüffner's dots.
  • Figure D shows a huge gametocyte, nearly 1½ to 2× the normal size of a red blood cell, also with Schüffner's dots.