Case #486 - February, 2019

A 10-year-old female patient from Argentina was taken to the hospital by her parent with complaints of “not feeling well.” A urine sample was collected and examined as part of the routine checkup. Microscopic examination of the urine sediment using the 40x objective lens revealed the following: 0-1 WBC and 0-2 RBC per field and a motile organism shown in the video that was sent to the DPDx team for identification. Still images of the organism were made by capturing screenshots at different points of the video (Figures AC). What is your diagnosis? Based on what criteria?

This case and video was kindly provided by the Hospital Clinicas de Cordoba/Universidad de Cordoba, Argentina.

Play VideoCdc-media

Parasitic image

Figure A

Parasitic image

Figure B

Parasitic image

Figure C

The organism shown in the video was an example of a rotifer, aquatic animals of the phylum Rotifera, and represented contamination of the urine specimen. The name “rotifer,” which means “wheel-bearer” in Latin, refers to the distinctive crown of cilia which in rapid motion appears to spin like a wheel. These organisms are also called “wheel animals” or “wheel animalcules” in recognition of their animal characteristics.

The diagnosis was based on:

  • overall body structure and characteristic motility
  • mouth with a crown of cilia
  • presence of a foot

For more information on rotifer please visit:

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.

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Page last reviewed: April 18, 2019