Microscopy

Trichuris trichiura eggs are 50-55 micrometers by 20-25 micrometers. They are football-shaped, thick-shelled and possess a pair of polar “plugs” at each end.  Eggs are passed unembryonated in stool.

A	B

A:  T. trichiura egg in an iodine-stained wet mount.
B:  T. trichiura egg in an unstained wet mount.

C	D

C:  T. trichiura egg in an unstained wet mount.
D:  Two T. trichiura eggs, showing the variability in size of the species.

E	F

E:  Atypical T. trichiura egg in a wet mount.
F:  Atypical T. trichiura egg in a wet mount.

G	H

G:  Cross section of an adult female T. trichiura stained with hematoxylin and eosin (H&E), showing numerous eggs.  Image taken at 100x maginification.  Image courtesy of the Oregon State Public Health Laboratory.
H:  Close-up of an egg in Figure G taken at 1000x magnification.

Macroscopic (Gross) Observations

Adult males of Trichuris trichiura are 30-45 millimeters long, with a coiled posterior end. Adult females are 35-50 millimeters with a straight posterior end. Both sexes have a long, whip-like anterior end.  Adults usually reside in the large intestine, cecum and appendix of the host.

I

I:  Image showing the posterior end of an adult T. trichiura, taken during a colonoscopy. Image courtesy of Duke University Medical Center.