Answer to Image Challenge 10

Image Challenge 10 was a case of malaria caused by Plasmodium vivax.
Diagnostic features are:

• Trophozoites are amoeboid and the parasitized red blood cells are enlarged (1.25× to 1.5×). Some are very distorted.
• In the image below , there is a trophozoite (see black arrow) that may be mistaken for a band form parasite, suggestive of P. malariae, however the red blood cell is reasonably enlarged. In infections with P. malariae parasitized red blood cells do not become enlarged.
• 
  Due to the type of stain used, Schüffner's dots (stippling) are not visible, however the other features are sufficient for a diagnosis of P. vivax.