Skip directly to search Skip directly to A to Z list Skip directly to site content
CDC Home
For questions about DPDx, contact us

Monthy Case Studies - 2012

Case #334 - October, 2012

During the laboratory component of the DPDx Diagnostic Parasitology Workshop on Intestinal Parasites, a participant made an observation on a trichrome-stained fecal smear and wanted to share with the class. The images in Figures A and B were captured at 1000x oil magnification. The two images show the same object in different focal planes. What is your diagnosis? Based on what criteria?

Figure A

Figure A

Figure B

Figure B

Show Answer

Answer to Case #334

The figures showed a trophozoite of Entamoeba coli with an ingested cyst of Giardia duodenalis. Diagnostic features included:

  • an amoeba trophozoite with coarse cytoplasm and within the size range for E. coli.
  • a single nucleus with an eccentric karyosome.
  • a large vacuole that contained a cyst within the size range for G. duodenalis demonstrating intracytoplasmic fibrils, two nuclei.

More on: Giardiasis

More on: Entamoeba coli

Back to Top

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.

For questions about DPDx, contact us
  • Page last reviewed November 29, 2013
  • Page last updated November 29, 2013
  • Content source: Global Health - Division of Parasitic Diseases and Malaria
  • Notice: Linking to a non-federal site does not constitute an endorsement by HHS, CDC or any of its employees of the sponsors or the information and products presented on the site. The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Road Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO