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Case #419 – May 2016
A 23-year-old female presented to her primary care provider with abdominal pain, cramps, flatulence, and diarrhea five days after returning from a white water rafting trip in the Grand Canyon, Arizona. Stool specimens were collected in 10% formalin and zinc polyvinyl alcohol (Zn-PVA) and sent to a reference lab for routine ova-and-parasite (O&P) testing. Figures A-D show what was observed on a trichrome-stain slide of stool preserved in the Zn-PVA. Images were captured at 1000x magnification with oil. What is your diagnosis? Based on what criteria?
![Case419_A.jpg](/dpdx/images/casestudies/2016/Case419_A.jpg?_=97780)
Figure A
![Case419_B.jpg](/dpdx/images/casestudies/2016/Case419_B.jpg?_=97883)
Figure B
![Case419_C.jpg](/dpdx/images/casestudies/2016/Case419_C.jpg?_=97902)
Figure C
![Case419_D.jpg](/dpdx/images/casestudies/2016/Case419_D.jpg?_=97983)
Figure D
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/.