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Case #513 – April, 2020
A 4-year-old boy went for a routine medical examination with his parents after they returned from a one-year sabbatical, studying primates in their natural habitat in central Africa. The child had no symptoms other than intermittent abdominal pain which started in the last four months of their stay in Africa. The parents reported seeing what appeared to be motile, rice grain-like objects in his stool recently. A stool sample was collected and processed for routine ova and parasite (O&P) examination. Figures A and B show what the technologist observed in the microscopic examination of the stool concentrate at 40x and 100x respectively. The objects measured 45-47 µm in diameter. What is your diagnosis? Based on what criteria?
This case was kindly provided by the National Public Health Surveillance Laboratory, Vilnius, Lithuania
Figure A
Figure B
This was a case of bertiellosis most likely caused by Bertiella studeri based on geographical location (Old World). Members of the genus Bertiella are cestodes (tapeworms) of non-human primates in nature. Human infections are uncommon. Morphological features include:
- Round to slightly oval eggs with an inner delicate, pyriform apparatus surrounding the oncosphere (green arrow, Figure B)
- Hooklets within the oncosphere (black arrow, Figure A)
- Size range within that listed for Bertiella studeri (35 – 51 µm)
 Figure A |
 Figure B |
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Images presented in the dpdx case studies are from specimens submitted for diagnosis or archiving. On rare occasions, clinical histories given may be partly fictitious.
DPDx is an educational resource designed for health professionals and laboratory scientists. For an overview including prevention, control, and treatment visit www.cdc.gov/parasites/.