TRICHURIS TRICHIURA

An estimated 604-795 million people in the world are infected with whipworm. Whipworm, hookworm, and Ascaris are known as soil-transmitted helminths (parasitic worms). Together, they account for a major burden of disease worldwide. Whipworms live in the large intestine and whipworm eggs are passed in the feces of infected persons. If the infected person defecates outside (near bushes, in a garden, or field) or if human feces as used as fertilizer, eggs are deposited on soil. They can then mature into a form that is infective. Whipworm infection is caused by ingesting eggs. This can happen when hands or fingers that have contaminated dirt on them are put in the mouth or by consuming vegetables or fruits that have not been carefully cooked, washed or peeled. People infected with whipworm can suffer light or heavy infections. People with light infections usually have no symptoms. People with heavy symptoms can experience frequent, painful passage of stool that contains a mixture of mucus, water, and blood. Rectal prolapse can also occur. Children with heavy infections can become severely anemic and growth-retarded. Whipworm infections are treatable with medication prescribed by your health care provider.

FAQS

What is whipworm?

Whipworm (Trichuris trichiura) is an intestinal parasite of humans. The larvae and adult worms live in the intestine of humans and can cause intestinal disease. The name is derived from the worm’s distinctive whip-like shape.

How is whipworm spread?

Whipworms live in the intestine and whipworm eggs are passed in the feces of infected persons. If the infected person defecates outside (near bushes, in a garden, or field), or if the feces of an infected person are used as fertilizer, then eggs are deposited on the soil. They can then mature into a form that is infective. Roundworm infection is caused by ingesting eggs. This can happen when hands or fingers that have contaminated dirt on them are put in the mouth, or by consuming vegetables or fruits that have not been carefully cooked, washed or peeled.

Who is at risk for infection?

Infection occurs worldwide in warm and humid climates where sanitation and hygiene are poor, including in temperate climates during warmer months. Persons in these areas are at risk if soil contaminated with human feces enters their mouths or if they eat vegetables or fruits that have not been carefully washed, peeled or cooked.

What are the signs and symptoms of whipworm?

People with light infections usually have no signs or symptoms. People with heavy infections can experience frequent, painful passage of stool that contains a mixture of mucus, water, and blood. The diarrhea typically has an acrid smell. In severe cases growth retardation can occur. Rectal prolapse can also occur. In children, heavy infection may be associated with growth retardation and impaired cognitive development.

How is whipworm diagnosed?

Health care providers can diagnose whipworm by taking a stool sample. By using a microscope, providers can look for the presence of whipworm eggs.

How can I prevent infection?

Avoid contact with soil that may be contaminated with human feces, including with human fecal matter ("night soil") used to fertilize crops.
Wash your hands with soap and warm water before handling food.
Teach children the importance of washing hands to prevent infection.
Wash, peel, or cook all raw vegetables and fruits before eating, particularly those that have been grown in soil that has been fertilized with manure.

Transmission of infection to others can be prevented by:

not defecating outdoors, and by
effective sewage disposal systems.

What is the treatment for whipworm?

Whipworm infections are generally treated for 1-3 days with medication prescribed by your health care provider. The drugs are effective and appear to have few side effects.

What is preventive treatment?

In developing countries, groups at higher risk for soil-transmitted helminth infections (hookworm, Ascaris, and whipworm) are often treated without a prior stool examination. Treating in this way is called preventive treatment (or "preventive chemotherapy"). The high-risk groups identified by the World Health Organization are preschool and school-age children, women of childbearing age (including pregnant women in the 2nd and 3rd trimesters and lactating women) and adults in occupations where there is a high risk of heavy infections. School-age children are often treated through school-health programs and preschool children and pregnant women at visits to health clinics.

What is mass drug administration (MDA)?

The soil-transmitted helminths (hookworm, Ascaris, and whipworm) and four other "neglected tropical diseases" (river blindness, lymphatic filariasis, schistosomiasis and trachoma) are sometimes treated through mass drug administrations. Since the drugs used are safe and inexpensive or donated, entire risk groups are offered preventive treatment. Mass drug administrations are conducted periodically (often annually), commonly with drug distributors who go door-to-door. Multiple neglected tropical diseases are often treated simultaneously using MDAs.

EPIDEMIOLOGY & RISK FACTORS

Whipworm is a soil-transmitted helminth (STH) and is the third most common roundworm of humans. Whipworm causes an infection called trichuriasis and often occurs in areas where human feces is used as fertilizer or where defecation onto soil happens. The worms are spread from person to person by fecal-oral transmission or through feces-contaminated food.

GEOGRAPHIC DISTRIBUTION

Worldwide, infection occurs more frequently in areas with tropical weather and poor sanitation practices, and among children. In 2002, the estimated number of persons infected with whipworm was 1 billion. Trichuriasis also occurs in the southern United States.

BIOLOGY

Causal Agent:

The nematode (roundworm) Trichuris trichiura, also called the human whipworm

Life Cycle:

Life Cycle of Strongyloides

The unembryonated eggs are passed with the stool. In the soil, the eggs develop into a 2-cell stage, an advanced cleavage stage, and then they embryonate; eggs become infective in 15 to 30 days. After ingestion (soil-contaminated hands or food), the eggs hatch in the small intestine, and release larvae that mature and establish themselves as adults in the colon. The adult worms (approximately 4 cm in length) live in the cecum and ascending colon. The adult worms are fixed in that location, with the anterior portions threaded into the mucosa. The females begin to oviposit 60 to 70 days after infection. Female worms in the cecum shed between 3,000 and 20,000 eggs per day. The life span of the adults is about 1 year.

Life cycle image and information courtesy of DPDx.

DISEASE

People infected with whipworm can suffer light or heavy infections. People with light infections usually have no symptoms. People with heavy symptoms can experience frequent, painful passage of stool that contains a mixture of mucus, water, and blood. Rectal prolapse can also occur. Heavy infection in children can lead to severe anemia, growth retardation, and impaired cognitive development. Whipworm infections are treatable with medication prescribed by your health care provider.

DIAGNOSIS

The standard method for diagnosing the presence of whipworm is by microscopically identifying whipworm eggs in a stool sample. Because eggs may be difficult to find in light infections, a concentration procedure is recommended.

PREVENTION AND CONTROL

The best way to prevent whipworm infection is to always:

Avoid ingesting soil that may be contaminated with human feces, including where human fecal matter ("night soil") or wastewater is used to fertilize crops.
Wash your hands with soap and warm water before handling food.
Teach children the importance of washing hands to prevent infection.
Wash, peel, or cook all raw vegetables and fruits before eating, particularly those that have been grown in soil that has been fertilized with manure.