Hepatic fluke

Hepatic fluke is a parasite that affects a person and can lead to the development of nonspecific symptoms that are difficult to explain and treat. This disease occurs more often than it is diagnosed, so it is important to have an idea of the main symptoms and clinical manifestations of this pathology. Infrequent diagnosis concerns other human helminthiases due to the nonspecific pattern and course of the disease.

All damages of the human body by worms are called helminthiases and are classified depending on the type of pathogen and the structure characteristic of this group. Distinguish:

1. Trematodes are so-called sysuns or flatworms - pathogens of schistosomiasis, dicrocoliosis, opisthorchiasis, fascioliasis;
2. Nematodes are roundworms, which are the causative agents of the following diseases - ascaridosis, trichocephalosis, trichinosis, enterobiosis;
3. Cestodoza - tapeworms, pathogens of the shadowyosis, shadoworhynchosis, cysticercosis, hymenolipidosis.

All these worms have different transfer mechanisms, different life cycles and different preventive measures. One of infrequent helminthiases is fascioliasis, the causative agent of which is hepatic fluke.

[1], [2], [3], [4], [5], [6],

Structure of hepatic fluke

Hepatic fluke or Fasciola hepatica has a complex life cycle and, given these characteristics and characteristic structure, it refers to flatworms.

The structure of the hepatic fluke is very characteristic for its class. The body is lanceolate or leaf-shaped, slightly flattened in the upper-lower direction with a characteristic color of dark brown color with a gray tinge. In the beginning and in the end the body narrows, has a pointed edge. The length of the parasite is not more than four centimeters, and usually about two to three and a half. Fasciola has two suckers, which are located on the anterior margin in the form of the oral and abdominal, and between them is a mouth opening. It is because of the presence of these suckers that these flat worms are called sisuns.

The digestive system of the hepatic fluke represents two tubes that do not have an open exit, but have a blind end without an anal opening. This is one of the advantages that helps the helminth parasitize in the hepatic ways.

Hemopoietic and respiratory systems are not fully developed, so the hepatic fluke has such a characteristic localization when it comes to the main and intermediate hosts.

The nervous system of the helminth is a nerve ring placed around the pharynx and nerve fibers in the form of long strands that run along the entire body and have branches to the different ends of the fluke. Such features of the nervous system allow you to react to changes in shape and other types of irritation of the fluke's body, despite the primitiveness of such a structure.

Reproduction of the hepatic fluke is a rather complex process that takes place with the change of various forms, hosts and brings a huge number of offspring from one egg. Reproduction of fasciolae passes through the sexual way and the hermaphroditic. This contributes to the fact that the life cycle of the hepatic fluke has three generations, each with its own larvae.

Such features of the external structure and characteristic differences in the internal structure of this helminth help the parasite affect primarily the liver and bile ducts, which allows it to be there without adverse effects on it of the aggressors of bile, hepatic enzymes and cellular lysosomal enzymes. Such activity of fasciola allows her to parasitize in the main place of her stay for a long time - about five years without the action of any immunity factors. This is often observed in helminthiases, that their primitive structure and rather complicated life cycle allows persist in the focus for years without pronounced clinical manifestations and reactions from the side of immunity. The owners of hepatic fluke are small and large cattle, and a man is not so often.

Life cycle of hepatic fluke

The complexity of the structure and the various forms of helminth reproduction require a complex life cycle. Fasciola has three generations:

• Marita with a larva named zircaria;
• sporocysts with larval miracidia;
• redia with a direct path of development.

The entire cycle of development begins with a hermaphrodite individual - marita. This marita lives in the owner and is a mature person. It has a characteristic long body, even more than a mature fasciola - about five centimeters. The structure of the marita makes it easy to distinguish this form from the others: at the end of a long lanceolate body is placed the uterus with the ovary, and along the entire length of the body the ovaries are located. Such a structure contributes to the fact that it fertilizes itself by having different genetic materials of two opposite individuals. Then, after some time, the fertilized eggs emerge from the uterus - they have a characteristic appearance: oval, brown with a yellow shade, have a lid on one of the edges or poles of the egg. After the eggs mature, larvae of miracidia come out of them, which also have characteristic features: the entire cell is covered with cilia outgrowths, which allows you to actively swim in the water, because immediately after ripening miracidia you need to find a host. At the front end of the cell is placed an organ that reacts to light, nerve fibers and a special substance that, when the body reaches the host, helps dissolve its cells and penetrate inside. At the end of the cell, there are special germ cells that give rise to the development of the next stage. These cells do not require fertilization, and development occurs in the asexual way. The first owner of the hepatic fluke is the mollusk. Miracidium penetrates with this proteolytic enzyme at the anterior end of the cell into the host, then migrates to the liver, where the new phase of development - the sporocyst - multiplies and forms in the asexual way.

The sporocyst has no characteristic features of the structure - it is a formless formation that does not have digestive, respiratory, excretory organs. They develop a new generation of larvae also from ready germ cells, which have remained from the previous cycle - redia. When the redias come out, the sporocyst shell breaks, and it dies, giving life to new forms. This generation already has organs - the digestive system is represented by a mouth opening, pharynx, and also there are organs that provide the outlet of new larvae. After one to two months, redia ripen and by simple division form offspring - circus.

Tsirkarii are the last stage in the life cycle of hepatic fluke. They already fully resemble the appearance and structure of an adult. At the front end of the circus have suckers, there is also a digestive tube and nerve ganglia, organs for the release of metabolic products. A distinctive feature in the structure is the presence in the circus of a long tail, which makes it possible for this form to leave the intermediate host and exist independently. Tsirkariya freely floats in water, and for further development is attached to plants near the shore, while covering with a capsule. Then a form is formed that is resistant to environmental factors and can withstand different temperature changes, drying due to a thick capsule. This form is a cyst and still has a specific name - adolescaria. The final owner is the animals that feed on grass or water plants - these are cows, horses, goats, pigs, sheep. Getting with food into the gastrointestinal tract of these animals, the hepatic fluke, being at the stage of cyst, dissolves its membrane under the action of enzymes of the stomach and intestines, and then penetrates into the wall. From the intestine helminth migrates through the blood of the portal vein into the liver, where is its habitat. Coming from the cyst, the larvae in the liver make long strokes and reach the bile duct, where finally their maturation and maturity occur finally three months later. Sometimes the helminth infects the pancreas. Then, nonspecific clinical symptoms begin to manifest, depending on the degree of damage to the liver cells and blockage of the biliary tract.

Ways of infection of a human liver fluke are limited to water bodies, where the intermediate hosts - mollusks live. Infection of the person happens infrequently, basically it is an accident or in the underdeveloped states at the use of water from the open reservoirs infected with cysts. It can also happen when eating raw unwashed vegetables or marine products. In the human body, the hepatic fluke is localized in the same place as in animals and causes the same changes as in the liver of mammals.

Symptoms of fascioliasis

The development of any helminthic lesion is accompanied by a number of nonspecific symptoms, but at the same time, characteristic symptoms are sometimes observed, which is associated with the peculiarities of the pathogenesis of the disease.

The defeat of the hepatic fluke is characterized by a predominant localization in the liver, namely in the bile ducts, but also frequent localization may be in the pancreas. At the stage of the larva, the helminth enters the liver, where it forms its hepatic passages, while hepatocytes are destroyed and characteristic clinical manifestations are observed. Cysts, due to their thick wall, are very resistant to the action of an aggressive secretion of bile. When fasciola reaches the hepatic ducts, it multiplies there, numerous eggs are formed, from which later adults develop and destroy the duct wall, expand it and disrupt the outflow of bile and the architectonics of the hepatic beams. When the eggs stand out with a portion of the bile in the gastrointestinal tract, only then can they be found in the feces.

The incubation period ranges from one to six to eight weeks. This is the period from the entry of cysts into the human gastrointestinal tract until they migrate to the liver and the onset of clinical manifestations. When the cysts are in the liver, they begin to multiply intensively and mature individuals attack the cells. This period lasts until all adult helminths are scattered over the liver. This period from the onset of the manifestation of the first symptoms to the reduction of the severity of the clinical picture is called the acute stage.

The acute stage with lesion of the hepatic cleavage is characterized by nonspecific manifestations in the appearance of fatigue, nausea, vomiting, headache, fever as to subfebrile, and to febrile digits. They can restrain severe pains or just heaviness in the right hypochondrium or in the epigastrium, as the left side of the liver is more often affected. Specific signs of liver damage is the appearance of jaundice, which has a greenish tint with intense itching. Such jaundice appears due to a violation of the outflow of bile and the release of indirect bilirubin into the blood, as well as an increase in the number of bile acids that can not enter the intestines and have irritant effects on the skin, that is, itching occurs.

In the acute stage, the symptoms of allergic manifestations are often observed, which can have a different degree of severity from skin lesions in the form of urticaria, to severe manifestations in the form of Quincke's edema. Such allergic manifestations are explained by the release of products of helminth metabolism into the blood, which has a strong allergic effect.

But such a pronounced clinical symptomatology is not at all and not so often. Quite often, helminthiases have an unexpressed acute stage, which greatly complicates the diagnosis. Symptoms may not be as pronounced, jaundice may not appear, and the only clinical manifestations may be nausea, vomiting, pain in the hypochondrium, which is often assessed as cholecystitis, cholelithiasis, or simple poisoning.

After a while, on average, from two to three weeks, the symptoms gradually fade and the next stage develops - chronic. The flow of this stage may differ, because there are different variants of the lesion. With the continuation of helminth parasites, the picture of chronic cholecystitis with periodic exacerbations develops. Helminths can cause disturbance of the rheological state of bile and this contributes to the formation of stones and the development of cholelithiasis. Very often small cysts of the hepatic double-leaf are not visualized on the ultrasound, which does not give reason to suspect anything else. When there is an infection of the biliary tract, then a picture of acute cholecystitis or cholangitis develops. All these pathologies develop against the background of just a small helminth that can live for ten years, and treatment will not be effective because of its nonspecificity.

Diagnosis of human injury by hepatic fluke

Due to the fact that the hepatic fluke has a number of nonspecific symptoms, as well as the severity of these symptoms may be insignificant, the question of timely diagnosis is very complicated. Often a diagnosis with the indication of the topic of the lesion in the life of a person is not put, since the eggs are not allocated constantly and may not be in all portions of the stool, but only a specific diagnosis can confirm the diagnosis.

As for the anamnesis, it is very important to find out from the patient when the first signs appeared. It is necessary to know about possible episodes of infection, asking about the last two months of life, given the incubation period.

When examining the patient, you can distinguish a symptom of jaundice, which is detected against a background of general pallor, as observed in more than 80% of patients with anemia. With palpation of the liver, it is enlarged, painful, there may be a round edge. Also, if the pancreas is affected, tenderness in the left hypochondrium may be observed. The gallbladder is often not affected, which can lead us to the idea of helminths, because jaundice is still expressed. But it can also be involved in the process due to hypertension in the bile ducts and a violation of the outflow of bile. Other clinical manifestations that can be seen are marked allergic signs, which are compared with symptoms of liver damage. All this will make us think about the possible helminthiasis.

Additional methods for diagnosing human liver damage with hepatic fluke are laboratory and instrumental.

Among the instrumental methods, ultrasound diagnostics is considered to be a priority. It allows to reveal the state of the gallbladder, possible inflammation of its wall in the form of a thickening of the wall, the presence of concrements in the bladder. It is also possible to measure the pressure in the ducts, their width and degree of damage. Ultrasound is carried out to a greater extent for the purpose of differential diagnosis.

Among the laboratory methods, laboratory feces are the simplest and most diagnostic. It is necessary to repeat this study repeatedly, because often the first time you can not find the eggs of a hepatic fluke or other helminth.

Conducted general clinical tests, among which a general blood test, a biochemical blood test. Changes in the general analysis of blood can be in the form of anemia. Eosinophilia will be evidence of helminthiasis. In the biochemical analysis of blood, the total bilirubin will be increased according to the degree of jaundice, mainly due to the indirect and direct in equal measure, which is confirmed by cholestasis. When determining hepatic samples - they may increase slightly according to the degree of cytolysis of hepatocytes, but the diagnostic value will be increased luzhnoy phosphatase, as a sign of violation of outflow of bile.

The most modern methods of diagnosing any disease to date are serological methods of research.

If the combination of clinical symptoms allows you to suspect fascioliasis, then to confirm, you can conduct a serological examination with the definition of antibodies to the hepatic fluke. When detecting a diagnostic titre of antibodies of immunoglobulin class M, it means that the patient has an acute period of the disease, and if the titre of immunoglobulins G prevails, helminthiosis has a chronic course.

Another progressive, to date, diagnostic method is a polymerase chain reaction, which involves the determination of DNA of the hepatic fluke in the patient's blood, which 100% confirms the result.

These are the main diagnostic methods that allow you to confirm the diagnosis and prescribe treatment in a timely manner.

[7]

Differential diagnosis of fascioliasis

Often the symptoms of different helminthiases can be similar to each other, which requires the allocation of certain patterns of development and clinical manifestations for the correct diagnosis and adequate treatment. As for fascioliasis, it must be differentiated with other helminthiases - Nematodoses and Cestodozums.

The difference between pinworm and hepatic fluke is very significant, but there are similar signs. Pinworms when a person is injured cause a disease called enterobiosis. Most often, children fall ill, but with an erased clinical picture, when no intestinal manifestations are expressed, allergic symptoms come to the fore. That is, as in the defeat of hepatic fluke, pinworm damage causes an allergic reaction, and often the parents turn to allergologists, because they can not diagnose the allergen that causes symptoms in their child. And this is just a defeat of helminth - pinworm. Therefore, if such clinical manifestations come to the fore, then it is necessary to distinguish enterobiosis from damage to the hepatic duodenum.

Distinctive features of the pinworm is, first of all, that these are two different sexes, which differ in size, and the eggs are deposited only by the female. Infection also occurs when swallowing eggs with unwashed hands or vegetables. The site of pinworm localization is the distal part of the small intestine and the proximal part of the large intestine. There is a release of individuals from the cysts, and then after fertilization, the female climbs into the distal rectum to the anus and lays eggs. This causes itching in the perianal region, which is a pathognomonic sign of pinworm damage. Specific diagnostics is carried out by identifying eggs in anal scrapes, as well as serological diagnostic methods - polymerase chain reaction and the detection of specific immunoglobulins.

Hepatic fluke and bovine tapeworm also have similar and distinctive features. The defeat of a bull chain occurs when a person consumes contaminated meat, which has not undergone sufficient heat treatment. Similar features are in the structure of both helminths. Bovine tapeworm also has suckers, with which it is attached to the cells of the intestine, it is a hermaphrodite. A characteristic clinical feature is also the presence of anemia and severe allergic manifestations, which can be even when affected by a hepatic cleavage. As for the symptoms, there is also weakness, dizziness, nausea and vomiting - these are all nonspecific manifestations of toxicosis in helminthiases.

A distinctive feature of the bovine chain is that it has a size of more than five meters and grows in the intestines, attaching suckers to the epithelium, which contributes to a strong slimming of the person, since it prevents the absorption of all nutrients. In the process of life, from the detachment segments are separated, and they crawl out through the anus, but they do not cause itching.

Diagnosis of the disease is difficult, because the parasite is difficult to identify and differentiate, and in the absence of treatment - it can live for a long time and the person grows thin and his immunity suffers.

A specific symptom can be considered the creeping of the segments, as well as laboratory diagnostics, which confirms the presence of specific immunoglobulins.

[8], [9], [10], [11], [12], [13],

Treatment and prevention of hepatic fluke

The treatment of all helminthiases is a rather complicated task, which is connected with the difficulty of diagnosis and the exact resolution of the diagnosis. Often to establish the type of pathogen precisely fails, so take into account the topic of the lesion and after that use complex treatment.

The treatment is aimed not only at destroying the pathogen, but also in correcting the disorders that have appeared, as well as with symptomatic maintenance therapy.

Etiological treatment involves the use of a special drug - Chloksil. This drug is available in the form of a powder and has an anthelmintic effect, directed at helminths, which are localized in the liver. There are several schemes for its reception. The two-day schedule provides for taking a dose in the calculation of 100-150 mg of the drug per kilogram of body weight of the patient, which is divided into two days. The five-day scheme is a drug intake in a dose of 50-60 mg per kilogram of patient's body weight, which are taken for five days. The powder is dissolved in half a glass of milk and drunk after eating. These two schemes do not have distinctive features, but must be determined individually. Such treatment is recommended in the acute phase of the disease. Symptomatic treatment is also necessary:

• with cholestasis prescribe drugs ursodesoxycholic acid, which stimulates the separation of bile and reduces the severity of jaundice;
• with fever, antipyretic agents;
• when the pancreas is affected, enzyme preparations are prescribed;
• for correction of anemia - food with high iron content;
• with the purpose of desensitization prescribe antiallergic drugs, mainly the first generation, if there is an itch, they will eliminate it.

This is the main treatment, and the drugs are selected individually, depending on the severity of clinical manifestations.

Prevention of lesions of the hepatic ligament can only be nonspecific, as there are no helminth vaccines. Prevention measures are reduced to sanitary and hygienic rules, which include:

• do not drink water from open sources;
• Always wash hands before eating;
• in the case of cooking in nature you can not wash vegetables in the river and pond;
• before taking fruits, vegetables, berries - they must be washed.

As for general measures, it is necessary to carry out isolation and purification of reservoirs that are the source of reproduction of hepatic fluke. Adhering to these rules - you can protect yourself and from defeat by many other helminths.

Liver fluke is a helminth that people can get infected with when consuming foods or water that are infected with cysts of this parasite. The disease is characterized by liver damage, which has a nonspecific character in the form of the development of cholestasis syndrome. Other organs can also be affected with the development of dyspeptic manifestations. Often against the background of intoxication of the body, which occurs under the influence of hepatic fluke, allergic manifestations develop. Given these facts, diagnosing this disease is not easy, nor is it easy to treat it. Therefore, it is necessary to follow preventive measures when preparing food and during meals.