Enterobiosis

Enterobiosis (Latin enterobiosis, English enterobiasis, oxyuriasis) is anthroponous contagious human helminthiosis, characterized by perianal itching and intestinal disorders.

ICD-10 code

Q80. Enterobiosis.

Epidemiology of enterobiasis

The source of infection is only the invaded person. The mechanism of infection is fecal-oral. The main factor of transfer of enterobiasis is contaminated with eggs, pinworms, as well as household items, toys. Eggs of pinworms are found on the floor, carpets, night pots, etc. Calculations due to severe itching in the perianal region contribute to the accumulation of eggs under the fingernails, where the larvae complete development before the invasive state. Sometimes retroinvasion is possible, when the eggs of the pinworm ripen in the anogenital zone, the larvae crawl back into the intestine and there ripen. Contagiosity is very high. Despite the short life time of pinworms, due to the possibility of frequent repeated infections, enterobiosis can last for years. Enterobiosis is ubiquitous, mainly in countries with a temperate climate. The intensity of the lesion depends to a large extent on the sanitary culture of the population. Enterobiosis mainly affects children of preschool and primary school age. According to WHO estimates, 350 million people are affected by this helminthosis, in Ukraine enterobiasis is the most common of helminthiases.

[1], [2]

What causes enterobiasis?

Enterobiosis is caused by the pinworm (Enterobius vermictdaris), belonging to the type Nemathelminthes, the class Nematoda, the order Rhabditida, the family Oxyuridae. Body adult helminths spindle-shaped: length of female 9-12 mm, male - 3-5 mm. In the female, the caudal end is pointed, and in the male it is spirally folded on the ventral side. Eggs asymmetric, oblong, 0.05x0.02 mm in size: their shell is transparent, with a double contour. A mature female parasitizes in the caecum. At night, when the sphincter relaxes, it independently exits through the anus and lays 5,000 to 15,000 eggs on the perianal folds, after which it dies. The embryo contained in the egg develops into the invasive larva for 4-5 hours. Eggs, relatively resistant to drying, pollute the bed linen and bed linen, where they remain invasive until 2-3 weeks. A feature of the life cycle of E. Vermicularis is the absence of a migration phase and low immunogenicity. The life span of pinworms from the moment of infection to the exit of mature females for oviposition is about 30 days.

Pathogenesis of enterobiasis

Pinworms cause mechanical damage during fixation on the intestinal mucosa, especially traumatizing its females with its long and sharp caudal end. Mechanical irritation and the action of the products of vital activity of helminths cause itching of the skin in the perianal zone. Pinworms sometimes plunge into the thickness of the intestinal mucosa, while around them are formed granulomas. As a result of the introduction of pathogenic microorganisms into the depths of tissues, pinworms can contribute to the development of tiflitis, appendicitis, and the worms themselves, penetrating the appendix, can cause appendicular colic. Ectopic migration of pinworms is the cause of vaginitis, endometritis and salpingitis in girls. Cases are described when helminths were found in the organs of the abdominal cavity in violation of the integrity of the intestinal wall caused by other diseases against which the invasion proceeded.

Symptoms of enterobiasis

Symptoms of enterobiosis are more pronounced in children; in adults, helminthiosis can be asymptomatic or subclinical. The most common symptom is itching in the anus. With low invasion, itching occurs periodically, as the next generations of female pinworms mature. Itching appears in the evening or at night, when the worms creep out from the anus. With intense invasion, itching and burning become permanent and debilitating, spread to the perineal region, genital organs. Prolonged and strong combing of itching places (around the anus, in the perineum, labia) promotes the skin's lichenization and the development of eczematous dermatitis, pyoderma, sphincteritis, and sometimes paraproctitis. Enterobiosis in many cases is the "trigger factor" of itching dermatoses of the anogenital area. Also patients, and especially children, note such symptoms of enterobiasis as irritability, poor sleep, increased fatigue; children are registered with fainting, epileptiform seizures, bedwetting. With massive invasion, there are violations from the digestive tract: pain and rumbling in the abdomen, flatulence, nausea, vomiting, constipation or diarrhea, sometimes with an admixture of mucus. When pinworms penetrate the appendix, the symptoms of an acute abdomen may appear in the appendix, in such cases the patients operate: in the remote appendix, catarrhal changes are detected, eggs and adult helminths are found in its lumen and thickness of the mucous membrane.

Complications of enterobiasis

Enterobiosis can have complications in the form of dermatitis.

[3], [4], [5], [6]

Diagnosis of enterobiasis

Adult helminths are sometimes found on the surface of stool. Diagnosis of enterobiosis is to identify eggs of pinworms - examination of the material (scraping) obtained from perianal folds with a tampon, spatula, transparent adhesive tape, a method of imprint using glass eye sticks with an adhesive layer according to Rabinovich. Recommend at least three repeated studies to completely exclude the possibility of invasion.

[7], [8], [9], [10]

Differential diagnosis of enterobiasis

Differential diagnosis of enterobiasis is carried out with other diseases, manifested perianal itching: hemorrhoids, rectum diseases (ulcerative, neoblastostnye lesions), diabetes, neurodermatitis, etc.

[11], [12], [13], [14]

Indications for consultation of other specialists

It is necessary to consult a gynecologist with itching in the genital area of women, consult a surgeon - with pain in the abdomen.

Indications for hospitalization

Antiparasitic treatment of enterobiasis does not require hospitalization of patients.

Treatment of enterobiasis

Treatment of enterobiasis consists in prescribing medications. The drugs of choice - albendazole, mebendazole, carbendacim: as an alternative - pyrantel.

Albendazole is prescribed by mouth: adults 400 mg once, children from 2 years - 5 mg / kg once; repeated reception in the same dose after 2 weeks.

Mebendazole is administered 10 mg / kg once; repeated reception in the same dose after 2 weeks.

Karbendatsim inside of 10 mg _; kg in three doses for 1 day; repeated reception in the same dose after 2 weeks.

Pyrantel is inside 5-10 mg / kg once; repeated reception in the same dose after 2 weeks.

Repeated treatment of enterobiasis with the selected anthelminthic drug is carried out after 2 weeks and is due to the fact that, due to the possibility of re-and superinvasions, one course may not have the desired effect. Indispensable conditions for successful dehelminthization in enterobiosis - the simultaneous treatment of all family members (children's team) and strict adherence to the hygienic regime to avoid re-infection. Before the treatment, a thorough wet cleaning of the room is carried out. A sick child is recommended to wash (shower), before going to bed, change underwear, wear panties, tight hips. In the morning, the child must be washed, change underwear, replace or iron bed linens with a hot iron. Daily cleaning should be carried out wet. The same is done with a repeated course of treatment.

Control over the effectiveness of treatment with the above parasitological methods is carried out 15 days after the completion of the course of treatment.

How to prevent enterobiasis?

Enterobiosis can be prevented by identifying the source of infestation and eliminating the pathways of transmission of the pathogen. For this purpose, once a year (after the summer period when forming a children's team or for epidemiological reasons), routine preventive examinations of children and attendants are carried out. Children who are sick with enterobiosis are excluded from visiting pre-school and educational institutions during the period of treatment and conducting a control examination. If 20% or more of those infected with enterobiasis are detected during routine preventive examinations in organized groups, in accordance with the normative documents, all children and staff are treated with anthelminthic treatment (twice with an interval of 2 weeks). In the focus of enterobiosis, it is necessary to strictly observe the cleanliness of the dwelling, office, school premises. Persons in contact with patients should observe the cleanliness of the body, clothes, wash their hands before meals and after visiting the toilet.

Prognosis for enterobiasis

Enterobiosis usually has a favorable prognosis.