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Monthy Case Studies - 2002
Case #87 - July, 2002
An 11-year-old boy with HIV was seen by a physician for gastrointestinal symptoms and failure to thrive. A duodenal aspirate was obtained and stained with modified acid-fast stain and heated safranin stain. The safranin stain was negative and the objects shown below were found in the modified acid-fast stained smears (Figures A and B). A wet mount evaluation using epifluorescence was also performed and the laboratory reported unspecific fluorescence. The laboratory submitted the modified acid-fast stained slides to CDC for diagnostic assistance. What is your diagnosis? Based on what criteria?
Figure A
Figure B
Answer to Case #87
The objects observed in this case were artifacts and a diagnosis was given of No Parasites Found (NPF). Although similar to oocysts of Cyclospora sp., there are several differences. Unlike Cyclospora oocysts, these structures are not uniform in size and shape. Cyclospora oocysts are predominately round, although rare damaged oocysts may be found. Like Cyclospora oocysts, these structures do not stain uniformly. However, Cyclospora oocysts that do not take up the stain are generally clear with a refractile appearance and do not take up the counter stain. The structure shown in Figure B is bluish-green because it was completely stained with the counter stain. The structures also did not have a clearly defined oocyst wall.
More on: Artifacts
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.
