Case #445 - June, 2017

Several people developed gastrointestinal symptoms of watery diarrhea, nausea with vomiting, and low-grade fever approximately 1 week after attending a catered event. Stool specimens were collected for laboratory testing which included a formalin-ethyl acetate concentration with brightfield wet mount examination.  Figures A–D show what was observed at 400x magnification in all of the specimens.  The objects of interest shown ranged in size from 8 to 10 micrometers   What is your diagnosis?  What other test(s), if any, would you recommend?

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