Case #468 – May, 2018

The object shown in Figures A–C was found in a stool specimen collected in SAF (sodium acetate-acetic acid- formalin) from a 43-year-old woman born and raised in Manitoba, Canada with no recent travel reported. Estimated length of the object was 8 millimeters. What is your diagnosis? Based on what criteria?

(This case and images were kindly provided by the Cadham Provincial Public Health Laboratory, Winnipeg, MB)

Figure A

Figure B

Figure C

This was a case of enterobiasis caused by Enterobius vermicularis (pinworm). Diagnostic morphologic features presented in this case were:

robust worm with cephalic inflations (Figure B).
long, slender tapered tail (Figure C) is a diagnostic feature of female worms of the species.
size of the worm was within that for female pinworms.

A follow-up inquiry to the provider of this case asking if eggs were observed in utero revealed that they were not; however the other features observed were still sufficient to make the diagnosis.

More on enterobiasis: https://www.cdc.gov/dpdx/enterobiasis/index.html

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/.