Dwarf tsepene - the causative agent of hymenolepidosis

Among numerous intestinal parasites of humans, dwarf tsepene or hymenolepis is known for its special infectiousness and vitality, since - unlike most other helminths, in particular, nematodes - it is able to reproduce in the human body and it is not so easy to clean the intestine from this flat worm.

The causative agent of hymenolepiasis, according to the taxonomic status accepted in parasitology, is of the type Plathtlminthes, class Cestoidea (tapeworms), subclass Cestoda (cestode), order Cyclophyllidea (cyclophyllide), family Hymenolepididae (hymenolepidid).

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Structure of the dwarf chain

Describing the structure of the dwarf chain, parasitologists note that its morphology is no different from the structure of other representatives of the class of tapeworms - intestinal anaerobic parasites of vertebrates.

The length of the adult body, that is, the dwarf chain ready for reproduction does not exceed 40-50 mm, and the width - 1 mm. The body of the parasite represents a strobila - a chain of two or three hundred repeating segments or segments (proglottids). Also in front of each worm there is a scolex (head) and neck. Scolex of the dwarf chain has four bots, (slit-shaped suckers), and between them - a retractable rostellum (proboscis), along the entire upper margin "armed" with about three dozen hooks. Thanks to this "snap" the tapeworm is easily fixed on the mucosa of the small intestine. Here, in the scolex, is the main nerve center (ganglion), from which along the entire strobila stretch the sensory and chemoreceptor nerve strings.

Immediately behind the scolex is the neck of the worm, during the growth of which the new proglottids are separated. That is, the maturing segments are gradually moved back to the end of the chain by the younger ones. And each segment feeds on its own and has its own hermaphroditic reproductive system, which works hard. And by the time the mature proglottid reaches the end of the body of the worm, it becomes a bag full of eggs. Then the segment simply detaches from the body of the worm and, performing its function, collapses, releasing the eggs.

The eggs of the dwarf chain (0.03-0.05 mm in diameter) are covered externally with a thin hyaline membrane and have a thickened inner membrane. In each egg there is a larval embryo (oncosphere) provided with hooks in diameter up to 0.015-0.018 mm.

There is no digestive system in the dwarf chain, and the ready nutrients from the host's small intestine are simply absorbed by the cells of the worm tegument-a multilayered surface tissue (7-15 microns thick) consisting of syncytium (multinucleated tissue), distal cytoplasm (having plasma membranes), glycocalyx ( layer of carbohydrate-containing macromolecules) and the proximal cytoplasm (inner layer that contains nuclei, endoplasmic reticulum, mitochondria, ribosomes, etc.).

The inner layer of the surface tissue of the dwarf strobila is limited to the basal plate, under which the muscle fibers are located, which ensure the body's ability to move. Nature has taken into account the fact that the nutrition of this species of cestoda occurs through endocytolysis, therefore, the release of metabolic products occurs through special cells - protonephridia.

By the way, it is established that complete dependence on the host, in which the parasite settles in the intestine, is associated with its inability to synthesize lipids. Moreover, lipids are necessary for dwarf chain and other cyclophyllides not as an energy source, but solely for gating - asexual reproduction.

Life cycle of a dwarf chain

In the majority of cases, the life cycle of a dwarf chain lasting approximately 30-45 days, occurs in one organism.

The causative agent of hymenolepidosis enters the body of a healthy person in the form of eggs, which come out of the intestine of the infected person with faeces. Outside the host organism, eggs with oncospheres retain their vitality for a short time, but this time suffices, that part of them "got attached" inside another host. The intermediate host of the dwarf chain is a man in whose intestine the hymenolepsis passes through an intermediate stage of its development. And the person in whose intestine this worm reproduces is the definitive or definitive host of the dwarf chain.

In the mouth of a person (and then in the intestine), the eggs of the parasite can be found together with food products on which flies have sat (mechanical carriers of any helminths), contaminated water, unwashed hands, dishes, in general, from any objects. If the adult dwelling place is the upper parts of the small intestine, then eggs can not enter the bowel movement, and then constant self-infection occurs. So the path of infection with dwarf chain, in the first case, fecal-oral, and in the second - autoinvasive. Children often become infected with himenolepidosis.

In the intestine of the final host - under the action of digestive enzymes - the hyaline membrane of the cestode eggs dissolves, and the larva embryo is free. Then comes the invasive stage of the dwarf chain, during which the oncosphere clings to the mucous membrane of the small intestine (to loose tissue at the base of intestinal villi) and within a few days a dwarf ternacle or cysticercoid is formed. For a while, the Finn ripens until she has a scolex embedded in her body and a body with a caudal appendage.

But when the intestinal stage begins, the cysticercoid loses the caudal appendage, straightens the scolex, leaves the "hard" place and digs into the new intestinal villi to get more nutrients and develop further. Two weeks later, the mature segments of the strobila of the dwarf chain are filled with eggs, and everything starts in a new circle.

Symptoms of dwarf tselein

Symptoms of dwarf chain, more precisely, symptoms of hymenolepiasis, are due to the fact that adult worms and their larvae with their suckers and hooks damage a large number of intestinal villi - outgrowths covering the entire mucosa of the walls of the small intestine. This leads to ulceration and necrosis not only of the epithelial epithelium of the villi, but also to damage to deeper layers of the intestinal wall and capillary vessels. At the same time, general poor health, abdominal pain (sometimes intense), diarrhea or constipation, muco-bloody particles in the feces are noted. As a result of disorders of the intestinal microflora, the process of digestion is disturbed, which causes nausea, vomiting, heartburn and belching.

Moreover, due to damage by the parasite of the lymphatic and blood capillaries inside the villi, the intake of proteins, lipids and carbohydrates necessary for the body in the bloodstream is impaired. And dwarf tartar in a child (except for nausea and pain in the abdominal cavity) often leads to dizziness, fainting, loss of appetite and body weight, anemia, decreased activity, sleep problems.

The products of the dwarf chain metabolism lead to a general intoxication of the body, which are manifested by convulsions, deterioration of the ability to remember, increased nervousness, etc.

Parasitic invasion also causes allergic reactions, since the human immune system (in the intestine it is the lymphoid follicles and Peyer's plaques) can not help reacting to the foreign protein as an antigen. As a result, when infecting this helminth, skin eruptions, inflammation of the conjunctiva, and allergic rhinitis can be observed.

Diagnostics of dwarf chain

Considering the non-specificity of the symptoms of hymenolepiasis and the fact that in a third of cases the symptomatology is practically not manifested, the diagnosis of the dwarf chain is carried out on the basis of coprovooscopy - the laboratory analysis of feces for the presence of eggs of this type of tapeworms in it. And the analysis is given three times - every 14 days (which is related to the life cycle of the parasite).

An enzyme immunoassay may also be required (for the presence of antibodies). And in severe cases of invasion, a hardware diagnosis is used - ultrasound or CT of the intestine and abdominal organs.

Treatment of a dwarf chain

To completely expel the parasite from the small intestine, treatment of the dwarf chain should be prescribed by the doctor, since in some cases the course of taking anthelminthic drugs must be carried out repeatedly - with a control test of the feces.

The most commonly used drugs are from pygmy tartar, like Fenasal (other trade names - Nichlosamide, Nichlosamide, Yomezan, Cestocide, Devermin, Helmiantine, Lintex) or Biltricid (synonyms Praziquantel, Azinox, Cesol).

Fenasal (in tablets of 0.25 g) does not enter the blood from the digestive tract and acts directly on the parasite, disrupting its intracellular metabolism, which leads to the death of the worm.

Tablets should be taken 4 times a day; daily dose for adults and children after 12 years - 8-12 tablets (2-3 g). If a dwarf tsepene is found in a child of 5-12 years, 6 tablets (1.5 g) are prescribed during the day, 2-5 years - 4 tablets (1 g). A child younger than two years should have 2 tablets (0.5 g). The tablets are chewed or crushed, mixed with a small amount of water, and drunk one hour before a meal, and then every two hours. The first course of treatment lasts 4 days, and after a 4-day break, the second course of Fenasala is administered. The compulsory procedure exactly two weeks after the second course is coprocopy.

Also treated with dwarf tincture Biltricidom (available in tablets of 0.6 g). This drug paralyzes intestinal parasites, and they fall away from the intestinal mucosa. Tablets are used inside after eating (without chewing and washing with water). The dose is calculated depending on body weight and age (20-60 mg / kg). Reception can be either single (before bedtime) or multiple-at 5-hour intervals. Biltricide is contraindicated in children under 4 years of age, pregnant and lactating women, and side effects of the drug are manifested by nausea, vomiting, diarrhea, headache, increased drowsiness and retardation; can temporarily rise blood pressure and temperature, as well as appear rashes on the skin.

Treatment of a dwarf chain by alternative means

Doctors-parasitologists treatment of dwarf tangerine by alternative means, for understandable reasons, are rather skeptical. For example, tips to make garlic enemas, or eat plenty of sauerkraut or bitter pepper ...

However, some alternative ways have a right to exist. To such phytotherapeutic agents it is possible to carry broths of bitter wormwood or tansy. Infusion of tansy flowers is prepared at the rate of 10 g (a teaspoon) per cup of boiling water. In large doses, the plant is poisonous, so you can take this broth only adults - three times a day, half an hour before meals.

Wormwood decoction (a dessert spoon of a dry plant for 250 ml of water) is recommended to drink 60 ml three times a day. But the greatest anthelmintic effect will be when using a wormwood powder, which is very simple to make from a dry plant with an electric coffee mill. Such a powder should be taken on a teaspoon 4-5 times a day, mixing with honey or washing down with a small amount of water.

Herbalists advise to cook powder at once of their three components - dry herb wormwood, tansy flowers, as well as culinary spices of cloves (taken in equal amounts).

The phenolic compound eugenol, which is rich in cloves, has biocidal properties. A tansy contains monoterpine (thujone), which stimulates peristalsis of the intestines, due to which, most likely, it is famous for its powerful means for fighting pinworms and ascarids.

Prevention of dwarf chain

Prevention of dwarf chain is possible and necessary. The main preventive tool - clean hands, the use of only carefully washed fruits and vegetables, as well as the identification of patients with himenolepidosis and their treatment.

Defuse eggs dwarf chain can only be processed dishes (kindergartens, catering) boiling water. The dishes should be stored in dry condition and in closed closets - so that flies do not sit on it, which is not in the kitchen of the kindergarten, in the cafe, or in the apartment.

Vegetables and fruits can be kept in hot (+ 65-70 ° С) water for 10-15 minutes, or it is good to wash in running water, allow it to drain, and then remove it for 40-45 minutes in a refrigerator (with a temperature not higher - 3-4 ° C).

And patients with hymenolepiasis should be identified and treated. And going on vacation to countries with a hot climate, you should be especially cautious and observe the rules of personal hygiene. For example, in Egypt, 22% of children aged 5 to 16 years found dwarf tseleen, which leads to anemia and a deficiency of vitamins B9 and B12 in the body.