Analysis of feces for enterobiasis: how it is carried out and how to prepare for it

Enterobiasis is the most common type of helminthiasis (prevalence reaches 70%), caused by parasitic roundworms. Enterobiasis is especially widespread in children's groups, since the leading factor of enterobiasis is insufficient personal hygiene skills.

The prognosis for this disease is favorable, provided that deworming is carried out in a timely manner. To diagnose enterobiasis, it is necessary to scrap the perianal folds (areas of the skin surrounding the hemorrhoidal ring). The analysis of feces for enterobiasis is not carried out, since the females of the parasite lay their eggs outside the intestines, which does not allow them to be detected in fecal masses.

Causative agent of infection

Human enterobiasis is caused by round worms of the pinworm genus. Pinworms can parasitize in the distal part of the small intestine and the cecum (the muscular cavity appendage from which the digested food begins its movement into the large intestine), as well as the central part of the large intestine, which is the colon intestine.

Pinworms reproduce by mating, which occurs in the ileum of the small intestine.

After mating, the male dies, and the female of the parasite, whose body can contain up to 800 eggs, moves into large intestine, from where it leaves the anal canal through the rectum and lays eggs on the skin of the perianal folds.

In the process of laying eggs, pinworms also secrete a toxic secretion that causes a strong skin irritation and excruciating, unbearable itching, which determines the main clinical sign enterobiasis.

Pinworms feed on food that enters the intestines, therefore, with prolonged invasion in an infected person, they quickly develop various forms of anemia and disorders caused by a lack of vitamins, essential acids and minerals substances. It is known that pinworms can absorb up to 50-60% of all nutrients entering the human body with food, therefore the clinical picture of enterobiasis can be supplemented by general clinical symptoms: weakness, lethargy, headaches, a feeling of chronic tiredness.

Features of the structure of pinworms:

• body length can reach 10-12 mm (the size of males is 2 times smaller than that of females);
  

  Male and female pinworms

• the color of the helminth is white, gray-white or milky;
• to the mucous cells that make up the intestinal membrane, the parasite is attached with the help of a vesicle - a suction cup located in the head of the body around the mouth opening;
  

  With the help of suckers on the head, pinworms are attached to the mucous membrane

• eggs have an elongated, oblong shape and are covered with a transparent shell.

The life cycle of parasites is about 20-30 days. Eggs ripen very quickly: it takes no more than 6 hours to reach the larval stage.

Important! There is evidence of the possibility of pinworms to parasitize in the appendix - the vermiform appendage of the cecum. The connection of acute inflammatory processes (appendicitis) with pinworm infestation has not yet been proven, but doctors suggest that with most likely, pinworms can cause blockage of the ducts of the appendix, causing intoxication and local inflammation.

Routes of transmission and source of infection

The source of infection with enterobiasis is always a sick person. If the patient does not adhere to careful hygiene during the period of invasion, eggs may be deposited from the skin of perianal folds on surrounding objects, furniture and other surfaces. Enterobiasis spreads especially quickly in children's groups, since pinworm eggs enter the body orally from dirty hands.

Sources of infection can be not only toys and objects that an infected person touched, but also raw water, as well as dust, which can contain a large number of eggs.

In order for the parasite to reach the stage of a mature individual, it needs certain conditions, primarily climatic ones. The optimum temperature for the growth and reproduction of pinworms is between 33 ° and 37 °. The humidity indicator is no less important: it should be about 80-90%.

The habitats of helminth eggs in the human body can be not only the intestines and appendix, but also:

• other internal organs (pancreas, liver);
  

  Parasites can inhabit the pancreas and liver

• skin under the horny plate of the nail;
  

  Eggs can accumulate under the nails

• genitals (in women, parasites most often penetrate the folds of the labia majora and small labia and the vaginal tract).
  

  Sometimes eggs develop in the folds of a woman's genital organs.

In the absence of food (chyme, rotting products), helminths can damage small blood vessels and feed on blood. Clinically, this is manifested by the presence of traces of blood and blood streaks in the fecal matter.

Note! If an infection is detected in a child's collective (for example, a group in a kindergarten), deworming measures are applied to all pupils, workers and their families. When cases of enterobiasis are detected, the group is quarantined, during which sanitary and hygienic treatment of the premises, furniture and toys is carried out.

Clinical picture

The main symptom of enterobiasis is intense, unbearable itching in the perianal region, which occurs mainly during sleep at night. In some children, itching sensations appear before a night's rest: experts believe that this phenomenon is of a psychosomatic nature and arises as a defensive reaction. Burning and itching can be so strong that the patient's sleep is disturbed, and strong scratching and irritation occur in the place of localization of itching sensations.

If a child scratches the skin until it bleeds and does not observe the necessary hygiene regime, there is a high risk of a secondary fungal or bacterial infection. For this reason, it is necessary to consult a doctor for a diagnosis if even a slight itching in the area is found. anus (the child scratches his buttocks, constantly pulls his hand to the anus, often wakes up at night, complains of a burning sensation and tingling).

Note! The first episodes of anal itching in an infected person appear about 20 (less often - 30 - 40 days) after the infestation by helminths. The duration of itching during this period is usually 3-4 days, after which it goes away spontaneously. The reappearance of clinical signs occurs after about 2-3 weeks: this is how long it takes pinworms for the larva to reach the stage of puberty and become able to lay eggs.

Other symptoms

Among other clinical manifestations of enterobiasis, requiring diagnostic procedures, the following signs can be distinguished:

• increased gas production, accompanied by bloating and the discharge of a large amount of intestinal gases with a pungent, fetid odor;
  

  Bloating accompanied by the discharge of corrosive gases

• rumbling in the stomach that occurs regardless of food intake;
• pain in the central and lower abdomen, which may be dull or cramping;
  

  Sharp and frequent abdominal pain is a common sign of enterobiasis

• an appetite disorder against a background of constant nausea (a fickle symptom, appears variably and depends on the life cycle of the parasite);
• vomiting (rare);
  

  Toxins from pinworms can induce vomiting

• false, painful urge to empty the bowels.

Stool with enterobiasis is frequent (up to 3-4 times a day), may contain a small amount of blood or mucous secretions. The feces have a gruel consistency and are light brown or yellowish in color.

The general condition of the patient is assessed as satisfactorily stable. A person may complain of sleep disturbances, headaches, loss of strength, and decreased performance. Very often, enterobiasis occurs against the background of a pronounced asthenic syndrome - a feeling of chronic fatigue that occurs against the background of an acute shortage of useful and nutritious elements.

Behavioral changes are often observed in children: the child becomes whiny, capricious, his academic performance in the classroom decreases, and interest in group games disappears. Severe itching can provoke bouts of uncontrolled aggression and irritability, which are also a reason for consulting a specialist.

Severe forms of enterobiasis

In most cases, enterobiasis ends in complete recovery of the patient without any pronounced health consequences. Severe forms occur with prolonged invasion, improper or untimely treatment, and non-compliance with the hygienic regime. Poor hygiene and lack of measures to combat itching can lead to infection in skin wounds and the development of a secondary inflammatory process.

In this case, other clinical signs join the main symptoms of helminthiasis, for example:

• spastic abdominal pain caused by the advancement of worms through the genital tract;
• inflammation of the inner lining of the uterus in women (with the advancement of worms into the uterus and vagina);
  

  Due to helminthiasis, the uterus can become inflamed.

• irritation of the abdominal space;
• purulent lesion of the perianal space (with the formation of single or multiple abscesses);
  

  If an infection enters the wounds around the anus, ulcers may form.

• inflammation of the muscle tissue surrounding the anal ring (sphincteritis).

Note! In some cases, a long-term current invasion of pinworms can cause the development of paraproctitis, a purulent inflammation of the tissues surrounding the anus with the formation of an abscess. Pathology is characterized by intense painful sensations, high fever, purulent discharge from the anus. Treatment of paraproctitis may require the use of surgical methods, so if any symptoms of enterobiasis are found, you should not postpone a visit to the doctor.

Analyzes for the diagnosis of enterobiasis

Many, upon suspicion of pinworm infection in themselves or their family members, turn to paid clinics and take a stool test. Such actions are ineffective, since they do not allow detecting enterobiasis. Female pinworms do not lay eggs in the intestines: this process takes place outside the rectum, and the skin becomes the place of egg deposition. For this reason, the only reliable tests for enterobiasis are a smear (scraping) from the skin of the perianal folds located around the anal ring, and the Graham method.

To diagnose an infection, you must contact a therapist, proctologist or infectious disease parasitologist.

Table. Diagnostic scheme for enterobiasis

Diagnostic steps	What's happening
First	Examination of the patient, collection of a medical history, clarification of the hygienic conditions of residence.
Second	Microbiological research.
Third	Laboratory blood test.
Fourth	Includes methods of auxiliary therapy for a complicated course of infection (examination by a gynecologist, ultrasound of the abdominal organs, consultation with a proctologist, etc.).

When to get tested

The main indication for diagnosing enterobiasis is severe anal itching of unexplained etiology, associated with other symptoms of infection (abdominal pain, nausea, stool disorder). Analysis is also required when applying for a job, in educational institutions or to obtain certificates in the pool. If a child is going to rest in a children's camp, he will also need to be screened for enterobiasis.

For prophylactic purposes, tests for enterobiasis should be taken 1-2 times a year.

How is the study going

The most popular method of microbiological examination for suspected pinworm infestation is a rectal-perianal swab (scraping). To carry it out, a cotton swab is needed, on which a 50% glycerin solution is applied (in some institutions, a 1% sodium carbonate solution is used). After receiving the biological material, it is scraped off onto a medical glass and sent to a laboratory for research.

A less popular, but more reliable method for diagnosing enterobiasis is the Graham study. The essence of the method consists in taking prints from the perianal area onto a special adhesive tape. With proper preparation, the efficiency of the method reaches 98%.

Note! Tests for enterobiasis must be taken three times with an interval of no more than 10 days. This need is associated with the life cycle of parasites and the characteristics of sexual maturation of helminths.

Preparation

Correct preparation for analysis is of great importance for obtaining reliable results. The study must be carried out in the morning (optimally from 7 to 10 hours) before the bowel movement. It is impossible to wash away before the study, as this can lead to a distortion of the clinical picture. For a comfortable analysis, it is enough to wash yourself with warm water with a special means for intimate hygiene (not with soap) the night before.

Blood test

To confirm the diagnosis and identify signs of helminthiasis, the patient is also assigned a detailed study of capillary blood. Indirect signs of enterobiasis will be the results shown in the table below.

Table. The results of a general blood test for enterobiasis

What the analysis shows	What it is	Physiological norm
Erythropenia	Decreased red blood cell (erythrocyte) count.	4.3-5.5 cells / l
Anemia	Decrease in the level of iron-containing proteins required for the transport of oxygen (hemoglobin).	115-140 g / l
Eosinophilia	An increase in the number of eosinophils in the blood.	1-5% of the total number of leukocytes

Despite the fact that a blood test for enterobiasis does not require special preparation, in order to obtain reliable clinical picture, it is recommended to take it on an empty stomach and quit smoking and chewing gum 8-12 hours before research. Also, the day before, you should not eat a large amount of fried and fatty foods, confectionery, spices and products containing alcohol (including liqueur-impregnated cakes and sweets with cognac).

How to treat an infection

For the treatment of enterobiasis, drugs from the group of anthelmintics are used. Most often they use Pirantel. This is one of the most effective drugs for the treatment of enterobiasis and mixed helminthic invasions. 1 tablet (or 5 ml of suspension) contains 250 mg of pyrantel.

The dosage of the drug depends on the age and weight of the patient and is usually:

• for children under 2 years old - 125 mg;
• for children from 2 to 6 years old - 250 mg;
• for children from 6 to 12 years old - 500 mg;
• for adolescents and adults - 750 mg.

If a person weighs more than 75 kg, the dosage must be increased to 1000 mg (these are 4 tablets or 20 ml of suspension). Pyrantel should be taken once a day after breakfast. Contraindications for treatment are myasthenia gravis (muscle weakness), as well as the period of breastfeeding and pregnancy.

When prescribing the drug "Pirantel", it should also be borne in mind that the active substance does not affect helminths in the larval stage, while the drug effectively removes eggs and mature individuals.

Table. Other drugs that can be used to treat enterobiasis

A drug	Dosage
Albendazole	The active substance is rapidly metabolized in the liver, and absorption in the gastrointestinal tract is no more than 5%. The daily dose for the treatment of enterobiasis is 400 mg. For children, the required amount of albendazole is determined at the rate of 6 mg / kg. Albendazole-based drugs are contraindicated in case of damage to the retina.
"Vermox"	An effective drug for the treatment of helminthic invasions, which has a fairly large number of contraindications, so it should be used only as directed by a doctor. The dosage is 100 mg once. In severe cases, the drug is taken at 100 mg 2 times a day for 72 hours.
Mebendazole	For the treatment of enterobiasis, 100-200 mg of mebendazole is sufficient once. The drug is prohibited in case of ulcerative colitis of the intestine, systemic lesions of the digestive tract and severe liver diseases.

For the treatment of the infection to be effective, it is necessary to adhere to a strict hygienic regime. It consists in frequent hand washing with antibacterial, household or tar soap, as well as thorough processing of underwear and bed linen.

Linen must be changed daily (underwear - 2 times a day), and it should be washed at a temperature of 60 ° -95 ° with mandatory subsequent ironing on both sides. All toys, furniture and other surfaces should be treated with disinfectant solutions that are safe for children and animals (for example, chlorhexidine solution). If there are animals at home, it is necessary to carry out preventive deworming with Milbemax, Cestal or Praziquantel.

Preventive measures

The prevention of enterobiasis is of great importance for the health of children and adults. To reduce the risk of infection, you should follow the recommendations of the health and hygiene professionals below.

1. It is necessary to instill hygiene skills (frequent hand washing, daily change of underwear) in children from an early age.
2. Wet cleaning and airing the premises must be done daily, as helminth eggs can mix with dust particles.
   

   Wet cleaning should be done more often.

3. It is better to use filtered water for drinking.
4. Before cooking, food (especially raw meat and vegetables with fruits) must be thoroughly washed with boiled water, and during cooking - to comply with the norms of heat treatment of individual food categories.
   

   Foods, especially fruits and berries, must be washed thoroughly before use.

Enterobiasis is the most common type of helminthiasis, according to statistics, which occurs in every second child aged 1 to 10 years. In rare cases, the infection can lead to serious complications, therefore, if you suspect enterobiasis, you must immediately pass tests and carry out the necessary treatment. For the prevention of pinworm infestation, adherence to the rules and regulations of personal hygiene, as well as proper handling of food, is of great importance. In children's groups, the prevention of enterobiasis includes regular sanitization of toys and premises, as well as an annual examination of children for pinworm eggs.

Video - Analysis of feces for enterobiasis