Case of the Week 597

This week's case is very timely, as we are seeing a lot of these objects in some of our stool specimens submitted for routine ova and parasite exam. They measure approximately 8-10 micrometers in dimension (shown at 500x and 1000x). What's the identification? What additional stain or study would you like to do?

Read Dr. Pritt's blog, Parasite Wonders, and submit your answers, comments, and questions. Also, visit her website ParasiteWonders.com, which hosts an archive of classic images from cases Dr. Pritt posted going back to 2007 (in an easy-to-search "A through Z" format) and also offers a flashcard feature.

Answer to Case 597:

Cyclospora cayetanensis oocysts, unsporulated.

Bobbi Pritt, M.D.

Bobbi Pritt, M.D.

Bobbi Pritt, MD, MSc, is a Professor of Laboratory Medicine and Pathology and the Director of the Clinical Parasitology Laboratory at Mayo Clinic in Rochester Minnesota. She is also the Chair of the Division of Clinical Microbiology. Her research interests are in clinical parasitology, vector-borne diseases and the pathology of infectious diseases.