Whipworm Infection

There are approximately 60 species of whipworms that infect mammals.  Only two are discussed here, the human whipworm, Trichuris trichiura, and the canine whipworm, T. vulpis.  These two species have a high degree of host specificity, but canine whipworms have been recovered from humans on rare occasions.

Whipworms get their name from the characteristic shape of the adults.  The adults live in the host's large intestine with their anterior ends embedded in the cells that line the intestine; each female can produce in excess of 10,000 eggs each day, and the worms can live for several years.

The whipworm life cycle starts with eggs from adult female worms living in the intestine being passed out with feces.  These eggs can then contaminate soil and, in warm moist conditions, they will develop to the stage where they can become infective in about three weeks.  These eggs are then swallowed, for example on fruits or vegetables that have been watered with water containing contaminated soil.  Once in the intestine, the eggs hatch into larvae, which grow and develop in the small intestine before moving to another part of the intestines – the cecum.  Here the adults attach themselves to the wall of the cecum and start producing eggs, which are then passed out with the feces.

Signs and Symptoms

Most infections of whipworms appear to be symptomless.  However, because the worms live a long time and a person can be reinfected constantly, heavy worm burdens can develop.  Symptoms of whipworm infection can include diarrhea, dysentery, and anemia.

Diagnosis and Tests

Diagnosis depends on the demonstration of eggs, which have a characteristic appearance, in the feces.  The biology of T. vulpis is similar to that of T. trichiura, and the eggs of the two species are virtually identical.

Complications

Heavy infections in children can cause mental and physical retardation.