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Whipworm Infection


By Richard D. Pearson, MD, Emeritus Professor of Medicine, University of Virginia School of Medicine

Whipworm infection is an intestinal infection caused by the roundworm Trichuris trichiura.

  • People acquire the infection by eating foods contaminated with soil that contains the roundworm eggs or by swallowing eggs after having contact with contaminated soil.

  • People may have no symptoms or may have abdominal pain, loss of appetite, diarrhea, bleeding from the intestine, or anemia, depending on the severity of the infection.

  • Doctors usually diagnose the infection by identifying eggs in a stool sample.

  • Adequate sanitation and good personal hygiene help prevent spread of the infection.

  • An antiparasitic drug such as albendazole is used to treat the infection.

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 800 million people are infected worldwide.


People acquire the parasite by

  • Swallowing food contaminated by soil that contains eggs

  • Transferring eggs from their hands to their mouth after contact with contaminated soil

Children may swallow contaminated soil.

The larvae hatch in the small intestine, migrate to the large intestine, and embed their heads in the lining of the intestine. Each larva grows into a worm that is about 4 1/2 inches long and is estimated to live 1 to 2 years, although some may live longer. Eggs are excreted in the stool.


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).


  • Examination of a stool sample

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 depends on

  • Adequate sanitation (particularly sanitary toilet facilities)

  • Good personal hygiene

Hands should be washed before handling food, and unwashed fruits and vegetables should be avoided.


  • Mebendazole, albendazole, or ivermectin (antiparasitic drugs that eliminate worms—antihelminthic drugs)

Mebendazole, albendazole, or ivermectin, taken by mouth, is used to treat whipworm infection. Sometimes a single large dose of mebendazole is adequate, but if infection is heavy, it is taken twice daily for 3 days. Albendazole taken daily for 3 days is an alternative. Neither mebendazole nor albendazole is given to pregnant women because these drugs can harm the fetus.

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