Case #358 – October, 2013

A 26-year-old female college student had undergone a homeopathic regimen advertised to eliminate parasites from the body. The only travel reported was to Maine a year ago to live with relatives on a farm between semesters. After experiencing recent mild to moderate abdominal discomfort, she sought medical attention to confirm that her home remedy was effective. A stool specimen was collected and tested for ova-and-parasites (O&P) by her primary health care provider. Figures A–C show examples of what was observed in low numbers in a formalin-ethyl acetate (FEA) concentration of the stool. Figure A is at 200x magnification; Figures B and C show the two objects of interest individually at 400x magnification. The objects measured 31 micrometers in diameter on average. What is your diagnosis? Based on what criteria?

Figure A

Figure B

Figure C

This was a case of taeniasis caused by Taenia sp. (Taenia solium, T. saginata, or T. asiatica). Morphologic features presented included:

brown, thick-shelled eggs with radial striations consistent with Taenia spp.
presence of refractile hooks within the onchosphere (best seen in Figure C).

Since the eggs of Taenia spp. are morphologically indistinguishable, attempts to examine proglottids and/or serologic testing should be considered since there may be a risk of cysticercosis to the patient and household members if the infection was caused by T. solium.