June, 2006

Case 181:
A patient was admitted to a hospital with a one-day history of fever and persistent headache on the right side.  Approximately 10 days prior to the onset of symptoms, the individual swam in a small swimming hole, associated with a river.  Two days after admission the patient developed a stiff neck, becoming progressively sleepy.  The patient became lethargic and unresponsive to pain stimulation, and treatment with acyclovir and manitol was started.  A computed tomography (CT) was performed and showed a lesion in the right frontal lobe and diffuse cerebral edema.  The patient was pronounced dead 6 days after the onset of symptoms.  Figures A and B are from hematoxylin and eosin (H & E) stained brain tissue specimens sent to CDC for confirmatory diagnosis.  Objects shown Figure B ranged from 10 to 12 µm in diameter.  What is your diagnosis?  Based on what criteria?  Which additional diagnostic test would you recommend to achieve a final diagnosis?

A	B

Click here for the answer to Case 181.

Case 182:
A researcher was studying parasites of public health concern found in snails and slugs.  A small portion of one specimen had tissue removed and placed in a small dish with a HCl/pepsin solution.  Many larvae were observed in the dish, however most were dead or dying, but a few larvae were active.  Figure A shows one of the active larvae in at wet mount captured at 200× magnification.  Figure B shows a larva under differential interference contrast (DIC) microscopy at 400× magnification.  What is your identification of the objects?  Based on what criteria?

A

B

Click here for the answer to Case 182.

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.