Welcome to the first case of the month, a regular feature by Idzi Potters and the Institute of Tropical Medicine, Antwerp. The following objects were seen in an unstained duodenal aspirate specimen. What's the identification?
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.
Giardia duodenalis (a.k.a. G. lamblia, G. intestinalis) trophozoites with "falling leaf" or "tumbling" motility.