Case #186 – August, 2006

A man went to a local hospital with abdominal pain and weight loss. He reported that he frequently travels to South America and had previously been diagnosed with ascariasis, although recent stool specimens were negative. The laboratory saw the objects in Figures A, B, and C in the patient’s stool samples. The objects measured 10 to 15 µm. Figure A was taken at 400× magnification from wet mount stained with iodine. Figures B and C were taken at 1000× magnification from a trichrome stained slide. What is your diagnosis? Based on what criteria?

Figure A

Figure B

Figure C

The objects are artifacts, probably plant material, and a diagnosis was given of No Parasites Found (NPF). Although the objects were morphologically similar to Cystoisospora oocysts (Figure D), they were smaller than Cystoisospora, which ranges from 25 to 30 µm.

Figure A