ShareCompartir
Monthy Case Studies - 1999
Case #7 - March, 1999
A hospital in Tennessee sent blood smears from a 49-year-old man to CDC. The man had traveled to Nigeria for nine days. He developed symptoms of malaria 12 days after his return. During his travel, he took some prophylaxis with chloroquine, but not in accordance with recommendations. When seen at the hospital, he was lethargic. The objects in Figures A and B were seen in his blood smears. Approximately 8% of his erythrocytes were affected. What is your diagnosis? Based on what criteria?
Figure A
Figure B
Answer to Case #7
This was a case of malaria caused by Plasmodium falciparum, ring-stage parasites. The diagnostic features observed were:
- a high parasitemia (8%).
- the presence of ring-stage parasites only.
- multiply infected erythrocytes. In Figure A below, there are four parasitized erythrocytes and three of them are multiply infected; in Figure B on the case studies page, an erythrocyte is infected with three parasites.
- appliqué forms (blue arrows on Figure A below).
- ring-stage parasite with double chromatin dots (red arrow on Figure A below).
While not diagnostic criteria, the travel history (Nigeria) and clinical history (approximate incubation period of 12 to 21 days, neurologic symptoms) are also compatible with P. falciparum.
Figure A
More on: Malaria
Images presented in the monthly case studies are from specimens submitted for diagnosis or archiving. On rare occasions, clinical histories given may be partly fictitious.
