Case #171 – January, 2006

Recently DPDx telediagnosis inquiries received a request for assistance from the Medical College of Wisconsin. Images from a thin blood smear were submitted along with the patient’s history of traveling to Honduras. Figures A-E show what was seen on the thin blood film. What is your diagnosis? Based on what criteria?

Figure A

Figure B

Figure C

Figure D

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

sturdy ring forms (Figures B and C).
amoeboid developing trophozoites (Figure A).
the presence of Schüffner’s dots (Figure A).
a schizont in an enlarged red blood cell with greater than fifteen merozoites (Figure D).

More patient information was provided later and gave the patient’s symptoms as fevers, chills, night sweats, and malaise that started several weeks after returning from vacation in Honduras. The patient reported to the attending physician that malaria prophylaxis was taken prior to and during the trip but discontinued upon return to the United States.