- About the Program
- Target Diseases
Whipworm (Trichuris trichiura [T. trichiura] or Trichocephalus trichiuris) is the third most common roundworm found in humans. The name "whipworm" refers to the shape of the worm; the worms look like whips with wider "handles" at the posterior end. Globally, nearly 800 million people are infected with whipworms, which are highly prevalent in children. Heavy infections could lead to short-term symptoms such as diarrhea and anemia and longer-term symptoms such as growth retardation and impaired cognitive development. Coinfection of whipworm with giardia, Entamoeba histolytica, Ascaris lumbricoides, and hookworm is common.
Whipworm infection, known as trichuriasis, is prevalent in both temperate and tropical zones of the world. However, infections follow a clustered distribution and are more frequently found in areas with tropical weather and poor sanitation practices. Whipworm infection occurs through ingestion of whipworm eggs, which can be found in fecally contaminated dry goods, such as beans, rice, and various grains, and in crops grown in soil fertilized with sewage. Humans are infected when such produce is consumed raw or food is contaminated by handlers.
Distribution of Whipworm
|Estimated Number of Whipworm Infections (in millions) by Age Group, 2003|
Life Cycle of T. trichiura
Step 1: Whipworm eggs are passed in the stool of an infected person.
Steps 2–4: In the soil, the eggs develop into a two-cell stage, an advanced cleavage stage and then develop into embryos. Eggs become infective in 15 to 30 days.
Step 5: Once consumed, the eggs hatch in the small intestine and move into its wall, where the larvae develop. When they reach adulthood, the thinner end burrows into the large intestine and the thicker end hangs into the lumen, where it mates with nearby worms. The females begin to lay their eggs 60 to 70 days after infection and shed between 3,000 and 20,000 eggs per day. Adults can live about 1 to 3 years, and females can grow to 50 mm (2 inches) long.
Trichuriasis symptoms range from asymptomatic through vague digestive tract distress for light infestations to emaciation with dry skin and diarrhea (usually mucoid and/or bloody) for heavy infestations. In children, heavy infections can lead to growth retardation. Longstanding bloody diarrhea leads to iron-deficiency anemia in many individuals. Severe cases can cause rectal prolapse. However, finger clubbing (swelling of the nails and area around the nails) is the best clinical predictor of the intensity of infection.
Source: VCD Kampala/Uganda
Whipworm infestation is usually diagnosed by microscopic examination of stool samples to detect eggs. The Kato-Katz is the technique of choice for diagnosis and quantification of infection with T. trichiura. Adult worms may be seen in a prolapsed rectal mucosa.
Treatment, Prevention, and Control
Mebendazole and albendazole are currently the drugs of choice to treat adult whipworms. In the case of light infection, successful treatment can be achieved with a single dose of 300 mg to 500 mg of mebendazole or with a single dose of 400 mg of albendazole. For heavy whipworm infection, 200 mg of mebendazole a day for 3 successive days or albendazole at 400 mg a day for 3 successive days is recommended. In the presence of iron deficiency, comprehensive treatment should be undertaken to solve the deficiency.
Prevention and control measures for trichuriasis are similar to most of the other soil-transmitted helminthes and include: