Case #338 – December, 2012

A 42-year-old pig farmer presented to his local medical facility with intermittent diarrhea and abdominal cramping. A stool specimen was collected in 10% formalin for laboratory testing. Figures A and C were captured at 200x magnification and show what was found in high numbers. Figures B, D, and E show a higher magnification (400x) of the same objects. What is your diagnosis? Based on what criteria?

Figure A

Figure B

Figure C

Figure D

Figure E

This was a mixed infection with Ascaris lumbricoides and Balantidium coli. Morphologic features shown in the figures included:

unembryonated, fertile eggs of A. lumbricoides demonstrating a thick wall (Figures A–D) and with a mammillated layer (Figures C and D).
large smooth-walled cyst of Balantidium coli (Figures A and B).
trophozoite of B. coli demonstrating cilia, a large macronucleus, and a cytostome (Figures C and E).