Case #480 – November, 2018
A man from New England returned from a trip to Africa with fever, chills, sweats, and fatigue. He sought medical attention from his health care provider. A blood smear was ordered, prepared, stained with Wright-Giemsa and examined. A diagnosis of Babesia was made. The slides and a blood specimen were sent to the CDC for confirmation. Figures A-D show what was observed at 1000x oil magnification on one of the stained blood smears. 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 falciparum. Diagnostic morphologic features shown, some of which also ruled out babesiosis, included:
- Thin, delicate rings, some presenting double chromatin dots
- Developing trophozoites with a few presenting malarial pigment (arrows Figure A)
- Macrophages presenting engulfed malarial pigment (arrows Figure C)
- Absence of pleomorphic parasites
There was some atypical presentation of the parasites in this case, such as extracellular parasites (Figure D, blue arrow) and even a multiply infected rbc with four parasites somewhat resembling a “Maltese Cross” (Figure D, blue arrow). However, even in this field one can see malarial pigment present in a developing trophozoite.
Figure A
Figure C
Figure D
More on malaria: https://www.cdc.gov/dpdx/malaria/index.html
Images presented in the dpdx case studies are from specimens submitted for diagnosis or archiving. On rare occasions, clinical histories given may be partly fictitious.