Fasciola

Fasciola (fasciola vulgaris) is a flat worm from the class of trematodes. It affects livestock and causes loss of live weight, reduction in milk yield and death of animals. In humans, fascioliasis (a disease caused by a hepatic ligation) occurs rarely. The source of helminthiosis is affected by fasciola. The geography of the spread of the disease is quite extensive, from countries with warm, humid climates (Peru, Chile, etc.) to areas with moderate climatic conditions (Belarus, France, etc.).

[1], [2], [3], [4]

Structure of the fasciolae

Fasciola has a flattened, leaf-shaped body. The length varies about 2-3 cm and the width is up to 1 cm. It consists of two parts - the beak-shaped anterior and broad posterior. The helminth has a pair of suckers of different sizes: smaller - oral, larger - abdominal.

The digestive tract of fasciola vulgaris has a branched anatomical structure. At the beginning of the fasciola tract, the oral sucker is placed, passing into the preorophage cavity, followed by the pharynx and esophagus, divided into branched loops of the intestine. Fasciola is a hermaphrodite. In the middle part of her body there are testicles, here are found: ovaries, vitellaria and uterus. The shape of the eggs of fasciolae is oval with a two-layered yellowish sheath. The size of the eggs varies, starting from 120 microns in length.

[5], [6], [7], [8]

Life cycle of the fasciolae

In its development fasciola passes several stages, accompanied by a change of hosts. Helminth eggs, released by the carrier into the external environment, enter the organism of the intermediate host, where the fasciolae form and evolve. Developing, the larva in different ways reaches the host organism, where its final sexual maturation takes place. Intermediate hosts of fasciolae are mollusks, snails that live in fresh water bodies.

The final host is a mammal (a representative of large and small cattle) or a person. Fasciola can live for several years in its bile ducts.

The owner of the parasite with feces allocates eggs of helminths to the external environment. Getting into the water, fertilized and viable eggs of the fasciola continue their development. The aqueous medium having a temperature of 22 to 29 ^on C, is optimal for the maturation of eggs and larvae emergence. Fasciola affects the initial stage of development of fasciolae low (below + 10 ° C) and high (above +30 ^о С) temperatures.

After 18 days out of the eggs come miracidia, adapted to life in the water. They penetrate into the body of the intermediate host, a small freshwater snail. After 1-2.5 months, after passing through the necessary stages of evolution, cercariae (caudate worms) appear. They leave the temporary master and again fall into the water.

Using suction cups, cercariae are attached to the leaves of aquatic plants and are selected from the cyst. For greater survival, the larvae are covered with a dense membrane. This period is called adolescaria - the appearance of larvae capable of invading the host organism. Adolescaria, with the presence of moisture well preserved (up to 1 year), but quickly die in an arid environment (after 3 months). The host organism receives the larva along with the contaminated water, fresh grass, poorly dried hay.

Adolescaria fasciola, hitting the lumen of the intestine, is introduced into the intestinal mucosa. From it the bloodstream penetrates the liver and is fixed in the biliary tract, where it begins to parasitize. With the blood flow through the vessels, the larvae can reach uncharacteristic places of parasitization in the body-the lungs, mammary glands, and skin. After 1.5-2 months after penetration into the organism of the final host, the fasciolae are transformed into a sexually mature individual with a hermaphrodite reproductive system. Having reached the formation and maturation of the reproductive system, fasciola is able to lay eggs. During the parasitic period, fasciola lays up to 2 million eggs.

[9], [10], [11], [12], [13],

Pathogenesis

The method of embedding the fasciola is oral. It occurs exclusively with the use of raw raw fresh water, unwashed greens, watered with cyst-infected fluke. Eating inadequately heat-treated goat or mutton liver infected with fluky larvae can lead to helminthic invasion.

[14], [15], [16]

Symptoms

The incubation period lasts from 1 week to 2 months. Infection can occur in two forms - acute and asymptomatic.

For an acute variant of the disease, allergic eruptions (urticaria), weakness, a rise in body temperature up to 39-40 ° C, cephalgia, pain in the epigastric region, in the right hypochondrium, nausea, vomiting, the appearance of icterus of the skin, hepatomegaly, tenderness and tightness of the liver are characteristic symptoms. With palpation examination. On the part of the cardiovascular system, the frequency of cardiac contractions increases, the heart sounds are muffled, without disturbance of the rhythm, there may be complaints of retrosternal pain. In the general analysis of blood - a significant increase in the number of eosinophils, leukocytes, an increase in ESR greater than 20 mm / hour.

Asymptomatic stage. It begins 1.5-2 months after the invasion. In this stage of the disease, the symptoms of gastroduodenitis are manifested (appetite is reduced, nausea, abdominal pain of fuzzy localization, unstable stool from diarrhea to constipation periodically appear), spasmodic pains in the right hypochondrium, disturbances in liver function are possible. In biochemical indicators of blood there are: increased values of ALaT, ASAT, alkaline phosphatase, GGTP, total bilirubin, violations in the protein composition of blood, decreased values of albumins, and an increase in the parameters of gamma globulins. In the picture of the general developed analysis of peripheral blood, the growth of eosinophils (up to 10%) is recorded, and minor anemia.

[17], [18], [19], [20]

Diagnostics

The diagnosis is made on the basis of clinical manifestations (a symptomatic complex of acute or asymptomatic variant of the manifestations of helminthic invasion), an epidemiological anamnesis (bathing or eating water from inactive reservoirs, using unwashed greens) and the results of diagnostic laboratory tests.

At an early stage of helminth infection, the study of a fecal swab using the Kato method will not give an informative result, because the allocation of eggs to the sexually mature specimen of the helminth occurs 3-3.5 months after ingestion and fixation in the hepatic ducts. At this stage, the main importance is the study of blood serum (the reaction of the RNGA, ELISA). In the asymptomatic variant of helminthic invasion or suspicion of fascioliasis, smear and stool examination using the Kato method or analysis of the contents of the duodenum can be effective. It is possible to detect the presence of eggs of fasciolae in feces and the contents of the upper intestine. In the asymptomatic course of fascioliasis, it is impossible to determine exactly at what time the helminth was introduced into the body and at what stage of puberty it is. Analysis of faeces is carried out twice with an interval of 7-10 days.

[21], [22], [23], [24], [25], [26],

Differential diagnosis

Differentiate the invasion of fasciola from allergic conditions, gastroduodenitis, hepatitis, cholecystitis, cholangitis, helminthiosis caused by other representatives (opisthorchiasis, enterobiasis, teniarinhoz, clonorchiasis, trichinosis), and others.

The difference between pinworm and fasciola

Externally, helminth fasciola is very different from pinworm. A symptomatology of invasion can be similar. Pinworms when introduced into the human body cause a disease called enterobiosis. They are often sick with children. When the clinical picture of intestinal intoxication is not pronounced, the intestinal symptomatology is not significant, skin allergic reactions can appear as a urticaria. As with infection with hepatic fluke, the introduction of the pinworms provokes a state of sensitization of the body and manifestations of skin reactions. It is necessary to seek help from a medical institution for immunologists-allergologists. It is difficult to identify an allergen that provokes acute reactions of the immune system. When conducting laboratory studies aimed at determining the allergen, it is possible to detect helminthic invasion. In such cases, it is necessary to differentiate enterobiosis from invasion by the hepatic cleavage.

The main differences are:

• Pinworms belong to another species of helminths, they are of opposite sex, only eggs are deposited by the female;
• Invasion occurs when you get from dirty hands, unwashed vegetables and fruits of helminth eggs into the food tract;
• The location of the pinworm is the large intestine. Here, individuals leave the cysts. After completion of fertilization, the female crawls to the anus and lays eggs, which causes itching and irritation in the anus. This is the main distinguishing feature of pinworm invasion. To confirm or refute the diagnosis, an anal scraping is prescribed, which determines the presence of eggs.

[27], [28], [29], [30], [31], [32]

The difference between fasciola and bovine tapeworm

Bovine tapeworm and fasciola have similar and distinctive features, and belong to different types of helminths. Invasion by tapeworm helminth bovine chain is possible when contaminated meat that does not undergo sufficient heat treatment gets into the food. Similarities are manifested in the structure of worms and the way they are fixed in the body of the main host. Bovine tapeworm is attached to the intestines with the help of suckers and is the hermaphroditic representative of the species. Similar and clinical picture at the beginning of the disease - the presence of anemia, eosinophilia, leukocytosis, skin allergic reactions, weakness, nausea and vomiting. The peculiarity of the bull chain is its huge size (up to 5 meters) and the full cycle of puberty and development takes place in the intestine. Its long presence in the human body leads to a pathological loss of muscle and fat mass and severe intoxication. Throughout life, after the puberty of the individual, from the helminth for the purpose of reproduction, segments (segments) are separated. They contain invasive larvae. Segments appear in the external environment through the anus, without causing itching.

Parasitic helminth is difficult to detect, diagnosis of the disease is difficult. In the absence of therapy, a person experiences abnormal weight loss and suppression of immunity.

The presence of fusions in feces is the main sign of the presence of bovine tapeworm in the body.

Treatment

Hospitalization is desirable in case of suspected invasion of the hepatic cleavage and at the stage of early manifestations of the acute form of the disease. Perhaps outpatient treatment.

In the early stages of the diagnosed disease, antiparasitic therapy is not prescribed, in order to avoid deterioration of the patient's state of health due to intoxication of the body with the products of the fasciola decay during her death. At this stage, the disease is prescribed symptomatic and palliative treatment. The doctor-helminthologist decides on the choice of tactics and methods of treatment. The following medicines may be prescribed:

Fermentosoderzhaschie - mezym; kreazim; panzinorm; kreon; enzystal and others.

Hepatoprotective and choleretic action - legalon; carsil; heptral; silegon; chophytol and others.

Antihistamines - zodac; claritin; cetrine; diazolin; aerius and others.

Affecting intestinal motility - duspatalin; sparex; niaspam; No-Spa, etc.

Probiotics - bifidum; florin forte; linex; bifiform, etc.

Infusion therapy to detoxify the patient's body.

In the presence of indications, antibiotics of a wide spectrum of action and medicines of other nosological groups are prescribed.

Therapy of antiparasitic action is indicated in the absence of symptoms characteristic of the acute form of the disease. Hexachlor-paraxylene (chloroxyl) 0.1 to 0.15 g / kg / day, biltricid (praziquantel) 75 mg / kg is used. Therapy is carried out under close supervision of the doctor.

Control tests should be performed regularly after 3 or 6 months of treatment.

Prevention of the fasciolae

To avoid infection with hepatic fluke, the following rules must be observed:

• Avoid using unboiled standing water from ponds. In the absence of an alternative source of water and the possibility of boiling, it is necessary to filter it through the fabric.
• It is mandatory to wash the greens (parsley, dill, coriander, etc.) with water followed by scalding with boiling water or blanching in boiling water for several minutes.
• To carry out preventive deworming measures for cattle: feeding with dry hay harvested and kept in the storage for 6 months, changing pastures, combating snails in reservoirs.
• Timely detect and de-worm patients with fascioliasis.

[33], [34], [35], [36], [37], [38], [39], [40],