Case #438 – February, 2017

A 36-year-old male immigrant, with an elevated eosinophil count, was suspected of being infected with pinworms and was administered a pinworm paddle test. Figures A–C show what was observed on the plastic paddle. What is your diagnosis? Based on what criteria?

Figure A

Figure B

This was a case of taeniasis caused by Taenia spp. Morphologic features shown in the images included small, brownish eggs with refractile hooklets and a thick, radially striated shell in the size range consistent with Taenia sp. (30-35 micrometers).

Since morphological identification to the species level is not possible by observation of eggs alone, obtaining mature proglottids for testing is recommended.

More on: taeniasis

This case and images were kindly provided by the Cadham Provincial Public Health Laboratory, University of Manitoba, Winnipeg, Canada.

Images presented in the dpdx case studies are from specimens submitted for diagnosis or archiving. On rare occasions, clinical histories given may be partly fictitious.

DPDx is an educational resource designed for health professionals and laboratory scientists. For an overview including prevention, control, and treatment visit www.cdc.gov/parasites/.