Whipworm infection (trichuriasis) is an intestinal infection caused by the roundworm Trichuris trichiura. Severe infection causes gastrointestinal symptoms.

Trichuriasis is a common infection, occurring mainly in the subtropics and tropics, where poor sanitation and a warm, moist climate provide the conditions needed for Trichuris eggs to incubate in the soil. About 1 billion people are infected worldwide.

People acquire the parasite by swallowing food contaminated by soil that contains eggs or by transferring eggs from their hands to their mouth after contact with contaminated soil. Children may ingest contaminated soil. The larvae hatch in the small intestine, migrate to the large intestine, and embed their heads in the intestinal lining. Each larva grows into a worm that is about 4½ inches long and may live for 7 to 10 years. Eggs are passed in the stool.

Symptoms and Diagnosis

Mild infections often cause no symptoms. Abdominal pain, loss of appetite, and diarrhea occur when a large number of worms are present in the colon. People with an extremely large number of worms, especially children, may have chronic diarrhea, weight loss, bleeding from the intestine, and anemia. Occasionally, a massive infection causes the rectum to protrude through the anus (rectal prolapse).

A doctor bases a diagnosis of trichuriasis on seeing the typical barrel-shaped eggs in stool samples examined under a microscope or occasionally by observing adult worms during a colonoscopy.

Prevention and Treatment

Prevention depends on adequate sanitation (particularly sanitary toilet facilities) and good personal hygiene. Hands should be washed before handling food, and unwashed fruits and vegetables should be avoided.

Mebendazole or albendazole, taken by mouth, is used to treat the infection. Sometimes a single dose of albendazole is adequate, but if infection is heavy, it is used daily for three days. Neither mebendazole nor albendazole is given to pregnant women because they can harm the fetus.

Last full review/revision March 2007 by Richard D. Pearson, MD