Case #422 – June 2016

A stool specimen was collected from a 10-year-old boy from Cambodia as part of a refugee screening program. The stool was collected in 10% formalin and sent to the local county health department for routine ova-and-parasite (O&P) examination. Figures A-F show what was observed at 200x magnification on a wet mount; Figures E and F were stained with iodine. The size of the objects ranged from 80-120 micrometers in length. What is your diagnosis? Based on what criteria?

Figure A

Figure B

Figure C

Figure D

Figure E

Figure F

The objects in this case were artifacts and a diagnosis of No Parasites Found (NPF) was given. Most of the objects appeared to be plant cells which may have resembled helminth eggs, although their size was typically larger than the eggs of most species seen in clinical human specimens. When iodine is added, a dark color is sometimes observed as an indicator that starch is present (best shown in Figure F).

More on: Atifacts

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/.