Parasitology Diagnostic Laboratory

Trichuris trichiura

The image below is a diagnostic egg of Trichuris trichiura from a patient stool . Although these roundworms are distributed worldwide, they are more prevalent in warm moist climates. The average egg measures 55 x 25 µm and is barrel-shaped. Ova have a smooth, thick, brownish shell with polar plugs at each end. Human infection occurs when eggs in contaminated soil are ingested. Larvae emerge in the intestine where they mature. Adult worms may live for more than 10 years and continue to pass eggs into the environment.