Trichiuriasis - Trichuris Trichiura

The trichiuriasis is a worm infestation caused by the parasite Trichuris trichiura a nematode about 4 cm long, which inhabits the large intestine of infected individuals.

Trichuris trichiura female
Trichuris trichiura female

What is trichiuriasis

Trichuris trichiura male
Trichuris trichiura male
The trichiuriasis is a very common parasitic disease in developing countries, where sanitation conditions are poor. The Trichuris trichiura is a parasite that is not well adapted to arid or extremely cold places, so the tropics, where the climate is hot and humid, are those with the highest number of cases of this parasitism. Worldwide, it is estimated that more than 1 billion people are infected with this parasite, most of them without presenting any symptoms.

Because the Trichuris trichiura live in environments with characteristics similar to those of the parasite Ascaris lumbricoides, it is very common co-infection by both nematodes. The Trichuris trichiura is a worm morphologically similar to Ascaris lumbricoides, however, it is much smaller, measuring on average about 4 cm from the usual 30 cm of Ascaris.

Transmission Trichuris trichiura

The trichiuriasis is a disease of fecal-oral transmission. An individual is contaminated with Trichuris trichiura when accidentally ingests tapeworm eggs contained in food, water or soil.

The life cycle of Trichuris trichiura can be summarized as follows: an infected individual releases thousands of tapeworm eggs every evacuation. If the feces come into contact with the ground, the eggs find a suitable place to mature. After about 2 or 3 weeks, the eggs begin to contain a worm capable of infecting the embryo who consume. Ingestion of eggs that have recently been eliminated in the feces is not capable of infecting others, for the embryo inside need this time 2 weeks of maturation in the soil in order to complete its life cycle.

In humid and with little direct sunlight environments, the eggs of Trichuris trichiura can remain viable for several months. On the other hand, dry, hot or direct sunlight, the egg and the embryo undergoes dehydration inside dies quickly.

The two most common forms of contamination are through contact of the mouth with hands that manipulated infected soil or consumption of food grown on land fertilized with human feces. Once ingested, the eggs of the parasite can pass through the stomach unscathed and hatch to reach the small intestine, releasing the worm larvae. After about 3 months, the larvae become adult worms and migrate into the large intestine where they will dwell definitely. Once in the large intestine, Trichuris trichiura can live for up to 5 years. The female of the parasite is able to put more than 20 000 eggs per day, which will be eliminated through feces, beginning a new cycle.

Symptoms of trichiuriasis

The vast majority of patients infected with Trichuris trichiura no symptoms. In general, only individuals with intestinal infested with hundreds of parasites that develop symptoms is trichuriasis. In these cases, the most common symptom is chronic diarrhea, which may or may not be accompanied by mucus or blood mixed with the stool. Abdominal distention, nausea, weight loss, anemia are flatulence and other signs and symptoms possible. A common physical sign is the digital clubbing, which is an enlargement of the fingertips and the nail.

A typical, usually signal present in children with massive contamination, rectal prolapse, one protrusion of the rectum through the anus. In such cases, we can see common worms attached to the lining of the rectum that is externalized.

Diagnosis of trichiuriasis

The diagnosis is usually made by trichiuriasis stool test, which can identify the presence of eggs Trichuris trichiura.

In some cases, the diagnosis can be done while performing a colonoscopy because the worms are found easily adhere to the mucosa of the large intestine.

Treatment of trichiuriasis

Treatment options for trichiuriasis are:
  • Mebendazole 100 mg, 2 times daily for 3 days.
  • Albendazole 400 mg, 1 time per day for 3 days.

In patients with massive infection, the treatment may be prolonged for 5 to 7 days. The cure rate in these schemes is often above 90%.

Three or four weeks after treatment, the doctor may order new stool test to confirm the cure. If there are still eggs, it is suggested to repeat the treatment.

Avoid the use of albendazole or mebendazole in pregnant women. In general, in infected pregnant women, the treatment is postponed until after delivery, to decrease the risk of toxicity to the fetus.
Parasite drugs
Related articles

General keywords

User discussion

Site indexMedicines onlineInteresting to readCommentaries © 2012