Case #309 – October, 2011

A 19-year-old male presented to his health care provider with moderate abdominal cramping and intermittent diarrhea that started approximately one week following a camping trip in the southeastern United States. A fecal specimen in 10% formalin was submitted for ova-and-parasite (O&P) examination. A formalin-ethyl acetate (FEA) concentrate was performed and Figures A and B show what was observed at 400x magnification in a wet mount preparation. The objects measured 17-20 micrometers on average. What is your diagnosis? Based on what criteria?

Figure A

Figure B

The objects shown in the figures were pollen grains (artifacts), and a diagnosis was made of No Parasites Found (NPF). The striations may mislead one to think of Taenia eggs, but the size was too small (Taenia eggs measure 30-35 micrometers) and the internal morphology was not consistent with Taenia eggs.