Animal nematodes. Symptoms of nematodes in humans. Directions of maintenance therapy

The body is filiform, fusiform, sometimes spirally twisted. The anterior end is blunt, and the mouth opening opens in it. The rear end is more often thinned, like a sharpened pencil, in males of the order 8gop%uSha it is expanded and ends with a bell-shaped bursa.

The musculocutaneous sac includes the cuticle, hypodermis, and muscles.

The cuticle covers the body from the outside, and also lines the inside of the oral cavity, anus and vagina, consists of three layers: external, intermediate and basal, formed by the hypodermis. The strength of the cuticle is given by collagen and keratin, which are part of it. Cuticle surface smooth or longitudinally and transversely striated. In some nematodes, the cuticle forms outgrowths, spines, warty growths, ridges, cords, plaques and swellings on the surface of the body. The swelling of the cuticle at the head end is called the head vesicle, on the lateral sides of the body - lateral, and on the caudal end - tail wings.

Under the cuticle is a single-layered epithelium, which forms the hypodermic layer of the cuticle. The boundaries of epithelial cells in this layer are visible only in young nematodes. In mature adults, these boundaries and the hypodermis take on the appearance of a syncytium consisting of a protoplasmic mass and nuclei. In the primary cavity, the hypodermis forms hypodermic protrusions called lateral fields or chordae. Chords are lateral, central and dorsal. They contain nerve trunks, and in the lateral chords there are also excretory canals.

Between the cuticle and the superficial layer of the hypodermis in nematodes of the subclass RIabtSha (Sesep1eShea) skin glands are located: the cervical gland, at the beginning of the intestine and the lateral tail glands or phasmids behind the anus. In subclass nematodes LrkaBtSha (Ac/eporYogea) phasmids are absent, but there are terminal-caudal glands, the excretory ducts of which open at the top of the tail.

The muscles are located under the hypodermis between the hypodermic ridges that divide the body of the nematodes into four sectors, two muscles each. In nematodes belonging to groups Noiotuagia, muscle cells line the inner surface of the hypodermis in a continuous layer and are divided only into two sectors by longitudinal hypodermic ridges.

In addition to the somatic muscles in the body of nematodes, there are muscles of individual organs, for example, lips, esophagus, rectum, egg and spicules.

The internal space in the body of nematodes is called the schizocoel or primary body cavity filled with insulating tissue. This tissue covers the internal organs of nematodes with a thin layer and consists of intertwining plates. Schisocoel regulates the osmotic pressure of nematodes.

excretory system consists of two channels located in the lateral chords of nematodes. Near the anterior end of the body, the excretory ducts join with each other to form the excretory sinus, which opens outwards with an excretory opening from the central surface of the body in the region of the esophagus.

Nervous system The nematode consists of a nerve ring surrounding the esophagus in the anterior half and longitudinal nerve trunks extending from it, from which nerve branches extend to all parts and organs of the nematode.

Digestive system represented by a tube that opens at the anterior end with a mouth opening, and at the posterior end with an anus (in females) or a cloaca (in males).

The digestive tube includes the oral cavity (stoma), pharynx, esophagus, midgut and hindgut. The mouth opening is located at the top of the anterior end of the body and usually opens thermally (forward), rarely dorsally. The mouth opening is sometimes surrounded by lips or cuticular lobes.

The stoma is the beginning of the pharynx. It has a different size and shape. Some nematodes (RiagSha) it is not expressed at all, but in others (Zіїop&ІShae) represented by a powerful vase-shaped capsule.

On the inner surface of the oral capsule at the entrance to it or at its bottom, there may be cutting formations of various sizes and shapes in the form of plates, teeth, stylets, hooks, etc.

The esophagus is surrounded by annular muscles, has a different length and shape, which is used in the diagnosis of nematodes. In some species, the esophagus is short, cylindrical, separated from the intestine by a slightly noticeable constriction. In other nematodes, on the contrary, it is long (in trichocephalates). In oxyurates, the esophagus is short, with a bulbous extension at its posterior end called the bulbus.

The rhabdiasis on the esophagus has two bulb-shaped extensions, of which the anterior one is called the prebulb.

In anisakids, at the junction of the esophagus to the intestine, a small area is isolated, called the ventricle.

Finally, in representatives of the trichuriat order, the esophagus is divided into two parts - the anterior muscular and the posterior glandular.

The intestine in nematodes is usually a straight tube. The walls of this tube are composed of variously shaped epithelial cells. The intestine may have blind outgrowths in the initial section, directed forward or backward, in the third - both forward and backward. The intestine ends with a posterior rectum separated from the middle part by a sphincter. In males, the ducts of the gonads open into the hindgut, forming a cloaca. The anal opening opens on the ventral surface and not far from the posterior end of the body and is very rarely terminal.

Sexual system. The male reproductive organs in most cases consist of a single filiform testis and a vas deferens, which flows into the rectum. The posterior section of the vas deferens has an extension - the seminal vesicle. In the cavity of the cloaca of males there are auxiliary organs: the stylus and rudder, rarely - the sexual cone, which contributes to the orientation of the male in relation to the female. Spicules in most cases enter the cloaca from the dorsal side and are enclosed in spicular sheaths. Most nematodes have paired spicules, but there are nematodes with one spicule, they can be colorless, yellowish or golden brown. The movement of spicules is carried out by muscles. Spicules, moving into the genital organs of the female, hold her at the time of fertilization.

The shape of spicules is very diverse: they can be short or long, massive or filiform, of the same size and shape or equal in size, etc., very rarely there are nematode species that do not have spicules.

The rule is a cuticular, suterized formation in the form of a thickening on the dorsal wall of the cloaca, which serves for the directed movement of the spicules.

The organs of the male reproductive system include the so-called genital sucker, located somewhat in front of the opening of the cloaca (ascaris).

In a significant part of the nematodes, a peculiar growth of the lateral parts of the body is formed at the tail end of the male due to the cuticular layer and, partially, the hypodermis and muscles. These formations are called the genital bursa. The sexual bursa is especially strongly developed in Strongylates.

The bursa in strongylates consists of two lateral and one dorsal lobes united by a cuticular membrane. There are ventral, lateral and dorsal ribs.

The female reproductive organs are most often represented by paired thin tubular ovaries, which pass into thicker oviducts, which, in turn, pass into the uterus, tubes of an even larger diameter. Two uterus, connecting together, form an unpaired organ - the vagina, which opens on the ventral surface of the female vulva. Often, part of the vagina is referred to as the "egg-shooter".

The opening of the vulva can be located on the ventral surface ranging from the excretory to the anus, i.e. in the region of the esophagus, tail or middle of the body of the female.

Nematode eggs are diverse in structure, some have a very powerfully developed shell, consisting of three clearly distinguishable shells, while others have less developed shells.

The outer and middle shells provide protection against mechanical stress. And the internal "lipoid" - from the chemical.

development cycle. The eggs are produced in the ovaries and travel through the oviduct to the uterus, where they are fertilized by sperm. After the egg is fully formed, it can be laid or remain in the uterine cavity until the larva is fully developed and even exits from the egg membranes. Females that produce eggs with a developed larva are called ovoviviparous, and females that produce free larvae are called viviparous. In any case, the larvae must complete their further development either in the external environment or in the intermediate host and become invasive, i.e. become capable of reaching sexual maturity when they enter the definitive host.

Some nematodes are able to develop only in one host (monoxenous). Other nematodes need their development in the change of two hosts (dixenous). The third group of nematodes needs to change three hosts (trixenae), of which one is final and two are intermediate.

Single-host nematodes develop without intermediate hosts. The definitive host becomes infected with helminths by swallowing infective eggs or larvae from the external environment from objects or with food, they are called geohelminths.

Nematodes that use two or three hosts for their development are called biohelminths, where the intermediate hosts are different animal species - both vertebrates and invertebrates.

Often, optional links are involved in the development cycle of nematodes, i.e. reservoir hosts, without which the nematode can do without in its development, but, despite this, the reservoir host often plays a significant role in the accumulation and preservation of invasion and its further transmission to the obligate host.

Roundworms are a spindle-shaped body of a round section, these have all the main systems of vital activity such as: digestive, reproductive, nervous, excretory, not only the circulatory and respiratory systems.

Observations have shown that the larvae and eggs of nematodes are stable in the natural environment.

Symptoms in humans and animals

The main localization in mammals is the gastrointestinal tract, during such an invasion it is noted:

• abdominal pain;
• diarrhea;
• lack of appetite;
• nausea;
• vomit.

With infection of the lungs and respiratory tract, it is noted:

• cough;
• dyspnea;
• pneumonia.

When the eyes are affected by larvae, the disease is accompanied by:

• conjunctivitis;
• tearing;
• decreased vision;
• In some cases, complete loss of vision is possible.

Common signs of finding nematodes in the body include an allergic reaction in the form of rashes, itching, redness, often a reaction to a foreign protein. Blood changes its parameters, there is an increase in eosinophilia. Toxic waste products cause general weakness, drowsiness, and mental breakdowns.

Diagnostics

Specialists use the biopsy method to identify complex invasions, as well as other methods of obtaining material for morphological diagnosis. The diagnosis of MRI, ultrasound, X-ray is not excluded. In addition, immunological diagnostics has been developed for the presence of antibodies to certain pathogens of nematoses in organisms using the methods of ELISA, RIF, RMP.

Treatment of nematodes

Drugs used for nematodes:

Prevention consists in observing the basic rules of personal hygiene. Pets and farm animals must be subject to mandatory periodic deworming.

In addition, the following activities are used:

• high-quality disposal of weeds;
• the use of individual inventory in certain areas / greenhouses (especially when diseased plants are detected);
• correctly alternate watering and drying the soil;
• properly fertilize the land with manure and plant plants.

The intracavitary fluid and internal organs are covered with ribbons of muscle tissue. Nematodes have a well-developed digestive, respiratory, excretory and nervous system. But in their body there are no blood vessels and respiratory organs, and waste products are released into the environment through the pores of the cuticle.

The clinical picture of trichuriasis (caused by whipworm) includes manifestations from the digestive system. There are pains in the epigastric region and next to the caecum. Therefore, this disease is often confused with stomach ulcers or appendicitis. Also, the acidity of gastric juice decreases, frequent headaches often occur.

Ankylostomiasis develops when hookworm or necator enters the body. These nematodes damage the epithelium of the digestive tract with oral capsules and feed on the excreted blood. Therefore, the leading symptom of the disease is anemia (decreased hemoglobin level). In addition to stool disorders, abdominal pain and nausea, patients complain of chronic weakness, constant fatigue, decreased performance, and dizziness.

Trichinosis develops as a result of Trichinella invasion. The incubation period can last up to several weeks. The disease begins acutely, with severe swelling and high fever, muscle pain, urticaria and other signs of intoxication.

Small larvae of the causative agent of toxocariasis, toxocara, quickly penetrate through the walls of the intestine into the systemic circulation, and then into various organs and tissues. These nematodes can cause nausea, flatulence, and abdominal pain. After entering the lungs and cardio - vascular system, toxocara cause shortness of breath, cough, cyanotic color of the nasolabial triangle.

Roundworms: transmission routes, possible complications and diagnostic methods

Roundworms are divided into two large groups: geohelminths and biohelminths. The life cycle of the latter occurs in the body of a single host, while geohelminths can change two or more hosts in the course of their development. Some nematodes affect only humans (for example, pinworms), others live in the intestines of humans, cats or dogs (Toxocara), wild and domestic animals (Trichinella).

During the day, the female helminth can lay tens of thousands of eggs, which are excreted in the feces and enter the soil. The exception is pinworms, which lay in the folds of the skin around the anus. Eggs can also be carried by some insects.

Roundworms enter the digestive tract as follows:

When ingested, nematodes primarily affect the functioning of the digestive tract. As a result of dysbacteriosis, the metabolism of the main biologically active substances is disturbed. A person suffers from a deficiency of vitamins and minerals necessary for the normal functioning of cells.

If necessary, conduct an instrumental examination of the patient. Procedures such as computed tomography of the lungs, brain, ultrasound of the abdominal organs, chest x-ray allow us to assess the extent of the spread of helminthic invasion and exclude other pathologies.

Intestinal nematodes: treatment methods in children, adults and during pregnancy

To remove intestinal nematodes, several drugs are used.

The most common are:

In pregnant women, intestinal nematodes become a real problem, since the vast majority of drugs are teratogenic, especially in the first trimester. In other words, their intake can lead to irreversible changes in the formation of the internal organs and systems of the fetus.

Almost the only drug that does not harm the body of a pregnant woman and the fetus is Piperazine (the dosage is from 400 mg to 4 g once). Also, clinical studies were conducted on animals about the influence of Decaris on the intrauterine development of the child. As a result, it was found that in the recommended dosage (up to 180 mg) the drug is safe. However, it is prescribed if the benefit to the mother outweighs the possible risk to the fetus.

Nematodosis: alternative medicine recipes, prevention

There are many folk remedies for the fight against helminthiasis. Doctors consider them ineffective, but they are ideal for pregnant women. Some recipes can also be used to treat helminthic invasions in children.

Herbalists advise using the following recommendations:

Nematodosis is a disease that is very difficult to avoid. Therefore, the child must be taught the rules of hygiene as early as possible. Already before enrolling in kindergarten, he should know that he should not put dirty hands and objects into his mouth, they should also be washed after walking, going to the toilet and before eating.

The rest of the preventive measures fall on the shoulders of the parents. Before eating fresh vegetables, fruits, berries and herbs, they must be thoroughly rinsed with running water. Meat, fish and seafood should be subjected to appropriate heat treatment, homemade milk should be boiled, and sour-milk products should be purchased either in their original packaging or from “trusted” sellers.

If there are pets in the house, they should be regularly given drugs to prevent helminthiasis, and after the street, carefully wash their paws and clean their hair. In the hot season, swimming in unsuitable water bodies should be avoided. In cafes and restaurants, dishes of dubious cleanliness should not be used, and disposable plates, forks and glasses are ideal for a hike or a picnic.

If a nematodosis was detected in one of the family members, everyone should undergo treatment without exception. Also, the room should be properly cleaned, bed linen and towels should be changed and washed in a timely manner. It is necessary to disinfect dishes, toys and other household items.

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How to determine the nematode?

How are nematodes diagnosed?

How to treat nematodes?

The modern drug Ricasol from NITA-FARM has demonstrated high efficiency in clinical trials and is recommended to livestock farms as the main tool for the treatment and prevention of nematodosis (including serious diseases - fascioliasis, paramphistomatosis, dicroceliasis). Rikazol is used for infection with various types of nematodes, cestodes, trematodes, mixed invasions.
The injectable form of the drug is made on the basis of ricobendazole, which is an active metabolite of albendazole.
Ricasol is administered 1 time as an injection. After 8 hours, the effect of its action becomes maximum.
It is equally effective against larvae and adults.
The effectiveness of the drug reaches 98-100%. It is used for infection of sheep, pigs, cattle.
Bioavailability - 100%: Rikazol is perfectly absorbed by the body and leaves with bile.
5 days after the start of treatment, milk is already suitable for use, meat - after 30 days.

Preventive actions

Drainage of areas for grazing should be carried out in a timely manner.
With a certain frequency, it is necessary to change pastures.
Premises where animals are kept should be regularly cleaned and treated with Ricasol.
Manure must be removed after it has been removed.
Veterinarians should administer Ricasol prophylactic injections in spring and autumn.