The trichuriasis belongs to the most widespread helminthoses (it struck about 500 million people). The infestant — Trichuris trichiura (threadworm) — is most widespread in the countries of hot climate, but meets also in the countries of a temperate climate, including in North America. The invasion seldom is followed by the expressed clinical symptomatology. Etiology. The person catches when swallowing mature eggs of a parasite (fig.) which are allocated with a stake and at optimal conditions of temperature and humidity of environment ripen during 2 — 4 weeks. From the swallowed mature eggs in intestines the larva which is implemented into a mucous membrane of a small bowel and remaining in it within 3 — 10 days hatches. Gradually ripening parasites leave in a gleam of a gut again and slowly go down in the blind and ascending gut to the place of the continuous dwelling. The name "threadworm" is given a parasite in connection with an originality of its outward. The front part of his body has a hair appearance, and back is thickened. Total length makes about 40 mm. The threadworm is fixed in intestines, being implemented into a mucous membrane front threadlike department of a body. Females begin to produce eggs in 1 — 3 month after infection of the person.
Fig. Threadworm egg in the smear prepared from svezhepoluchenny a calla (X1000). Epidemiology. The trichuriasis is most widespread among the population of the agricultural areas differing in low sanitary level. The person serves as the main owner of a parasite, children get sick most often. Infection occurs through dirty hands, the food infected with eggs of a worm and water. Eggs are transferred by flies and other insects. Clinical manifestations. In most cases the invasion remains asymptomatic. Some persons have feeling of discomfort in an abdominal cavity, gripes, abdominal distention. The adult individual of a worm exhausts during a day of about 0,005 ml of blood. Anemia, diarrhea with blood impurity to Calais and in rare instances a prolapse of the rectum occur only at children with extremely massive invasion. Diagnosis and treatment. The direct microscopy of smears svezhepoluchenny a calla allows to identify the threadworm eggs differing in characteristic outward. Treatment by Mebendazolum inside on 100 mg twice a day for 3 days provides deworming in 70 — 90% of cases. Considerably decreases and even allocation of eggs with a stake at 90 — 99% of patients stops.