Alveococcosis of the liver

Alveococcosis is an infectious disease because it is caused by infection with helminths( tapeworm detachment detachment).Another name - alveolar or multi-chamber echinococcosis. Pathology is characterized by a prolonged chronic course.

Alveococcosis of the liver occurs at a frequency of 44.2-84.2%( according to some estimates, 90%).The preferred localization of the consequences of the introduction of the parasite is in the right lobe of the liver( 2 times more often than other parts).This is explained by the more convenient circulatory conditions for the entry of the pathogen: the right branch of the portal vein is characterized by a relatively large diameter, and the angle of its departure from the main vessel is a blunt shape.

The defeat of the liver is tumor-like in nature, often gives metastases to other organs, especially the brain and lungs. In the International Classification of Diseases, alveococcosis is considered together with liver echinococcosis under code B67.5.

Features of the distribution of

In nature, there are geographical foci of alveococcosis. In them the pathogen circulates constantly in the blood of wild animals, which become sources of human infection. These include:

• countries in Central Europe;
• South and Central America;
• Alaska;
• northern Canada;
• Central Asia;
• of the Transcaucasus.

In Russia, the following are considered dangerous areas:

• Far East;
• the Ural region;
• Siberia,
• Kirov region.

The maximum frequency of alveococcosis distribution is determined by:

• in Yakutia;
• Krasnoyarsk, Altai and Khabarovsk Territory;
• of the Omsk and Tomsk regions.

Characteristics of the causative agent

The class of tapeworms( chain) to which the alveococcus belongs, parasitize mainly in the body of warm-blooded animals( birds, mammals).There are several species that affect a person. Development of alveococcus corresponds to the general rule of mandatory replacement of two hosts. The first is intermediate, the second is final.

The causative agent of alveococcosis of the liver is the larva of the alveococcus, called oncosphere. It is located inside each of many small bubbles( alveoli), which are fused together into a knot. The cavities are filled with a liquid of a yellowish color and a thick consistency, possibly having a mass of a darker appearance. In each vial is the germ of the parasite.

In the structure of the female worm distinguish:

• head or scolex with hooks( up to 30);
• neck;
• segments of 2-5 pieces containing the uterus with eggs.

microscope The bubble conglomerate is continuously growing by budding. Such a node is called a Finno or larvocist. Its structure is characterized by multichamber. Within each bubble is 1-3 heads of embryos. Increasing in size, the larvocysts form a cyst with a multitude of chambers.

The developmental cycle of alveococcus is similar to the causative agent of echinococcosis, but the disease is more severe due to the germinating nature of the spread of Finns from the affected liver. In addition, differences are determined when comparing sexually mature forms of worms: alveococci are smaller( less than 2 mm) and different structure of hooks, uterus.

Finn with an increase in volume compresses surrounding liver tissue as a tumor. Separation of vesicles with the embryo of the alveococcus and its spread with blood flow are similar to the process of metastasis.

Description of the node

The formed alveococcosis nodes( larvocysts) in the liver are histologically represented by the inflammatory response and necrosis of the parenchymal cells. They reach a size of 30 cm or more. On the cut, an off-white color is visible, the density is similar to a cartilaginous tissue. Inside there are cystic cavities. In the case of a direction of growth toward the surface, the alveococcal node of the liver is capable of germinating into the neighboring organs:

• the right kidney;
• diaphragm;
• bone;
• other fabrics.

Possible distant metastasis.

The reservoir of infection and the type of human infection

The reservoir for alveococcus are wild animals:

• foxes;
• wolf;
• arctic fox;
• coyotes.

Very rare - pets( dogs).Usually cats and dogs serve as carriers only for echinococcosis.

Intermediate distributors can be rodents:

• mouse-voles,
• gerbils,
• ground squirrels,
• muskrats,
• nutria.

In exceptional cases - a sick person.

Infection of wild animals occurs during eating of intermediate hosts of alveococcus( rodents) with larvocysts filled with larvae. In the intestines of predators( final hosts) adult embryos mature in very large numbers. This process takes 35 days. In segments, up to 800 oncospheres( eggs) are formed in each. Allocation to animals onkosfer lasts 7 months.

A person becomes infected when eggs of alveococcus enter the digestive system. This happens through the mouth by swallowing, if the rules for washing hands after contact with the coat are not observed. Less often, there are cases of infection after ingestion of unwashed, harvested berries in the forest, the use of herbs for folk treatment. They can be contaminated with animal feces.

Contact with eggs of alveococcus occurs:

• during walks and work in the forest, in the field;
• collecting berries and mushrooms;
• drinking water from rivers and streams;
• hunting;
• processing of hides;
• care of sick animals.

A rare mechanism of infection - the inhalation of feces contaminated with feces with oncospheres. In such cases, alveococcosis affects the lungs. Any person is susceptible to infection. Most often the disease spreads among the population from 30 to 50 years.

Mechanism of liver damage

Oncospheres of alveococcus enter the digestive tract through the mouth. In the human small intestine, the eggs lose their outer shell and are embedded in the wall. Further, they are absorbed into the blood, lymph vessels through the intestinal wall and reach the bloodstream of the right lobe of the liver. Other localization is a consequence of metastasis.

occur. There is a slow growth outside with the formation of additional vesicles and the replacement of hepatic cells with a connective tissue. At the same time, the structure of the organ is broken, the vascular network is destroyed, the liver is affected. In the future, biliary cirrhosis is possible.

Attachment of secondary infection provides further development of :

• of cholecystitis and cholangitis;
• abscess in the liver;
• mechanical jaundice.

In the case of suppuration of the multi-compartment cyst, its disintegration occurs.

The action of alveococcus on the human body

The ingestion of people with alveococcus causes reactions that are severe for health. The infected person has to deal with the consequences:

• sensitizing the body with the products of the vital activity of the parasite, which are toxins for humans;
• mechanical compression of tissues with a growing node( cyst), which leads to a serious impairment of liver function, increases the spread of toxins through the bloodstream, creates danger for other organs and systems;
• of mechanical jaundice, foci of necrosis in the liver;
• the formation of secondary foci( metastases) in the lungs, brain, heart, adrenal glands, spleen with a malfunction of these organs;
• the emergence of immunodeficiency, the development of an autoimmune reaction to the destruction of its own cells.

Symptoms of

Symptoms of liver alveococcosis appear several years after infection. Before that, a person does not feel sick, no complaints. A doctor suspects a disease if a dense, bulky, enlarged liver is found during examination. Physicians in endemic areas are especially wary.

Early stage - accompanied by:

• unstable dull pain in the right hypochondrium;
• with a sense of gravity;
• weakness;
• loss of appetite.

Patient examination already at this stage allows a dense knot to be palpated if it is located closer to the periphery of the liver. The laboratory analysis of blood for protein shows the growth of the total protein due to gamma-globulin fraction. Increases ESR.

For the stage of the height of the disease, the progression of all signs and symptoms of digestion disorders is characteristic:

• pains in the right hypochondrium become permanent and intense;after a meal a patient experiences a feeling of heaviness, belching;
• has a disorder of stool;
• is exacerbated by weakness;
• lacks appetite.

Palpation is determined by dense tuberosity due to inflamed areas of the liver, multiple nodes. Such a liver is called "stony".Laboratory indicators become sharper:

• appears a moderate increase in eosinophils( up to 15% of all leukocytes);
• significant acceleration of ESR;
• expressed disproteinemia( with an increase in the total protein to 110 g / l decreases albumin, but significantly increased gamma globulins);
• increase in C-reactive protein;
• growth of thymol test( a sign of inflammation of the hepatic tissue).

The stage of severe manifestations - most often accompanied by the development of severe mechanical jaundice:

• appears light feces and darkens urine;
• jaundice is visible on the color of sclera, oral mucosa, skin, has a persistent character, sometimes there is a greenish tint;
• severe itching of the skin of the limbs, back.

In this stage, alveococci germination from the liver into large vessels and the formation of secondary foci is possible. Therefore, the clinic appears:

• as signs of increased pressure in the portal vein - edema on the legs, ascites, varicose veins of the esophagus is accompanied by the danger of bleeding;
• in 50% of patients there are symptoms of glomerulonephritis, there may be a violation of urination, in the analysis of urine - erythrocytes, protein, pus, leukocytes.

Terminal stage - differs heavy current. There are violations of the function of not only the liver, but all affected organs. Their changes become irreversible. Patients are depleted, suffer from pain, complications against the background of severe immunodeficiency.

What are the possible complications?

If the patient's temperature rises sharply, pains increase, then we should assume:

• infection of cystic contents with the formation of liver abscess and its decay;
• mechanical jaundice can contribute to purulent cholangitis;
• if a cavity breakthrough occurs, the patient's pain increases, the temperature rises;
• inflammation of the fatty tissue around the liver( perihepatitis).

A serious complication is the germination of the node in the surrounding organs and tissues( gall bladder, omentum, kidney, ligament, through the diaphragm - into the lungs, pericardium bag, heart) and attachment of systemic amyloidosis with kidney damage and development of renal failure.

Diagnosis

In order to make the correct diagnosis, it is necessary to take into account the epidemiological anamnesis. It includes data for the previous several years:

• for lifestyle;
• contact with wild animals;
• of the territory of residence;
• hunting;
• professional risk.

For the final diagnosis, the following methods are used:

• laboratory methods - the changes in the general blood test, the violation of the protein ratio, biochemical tests of the liver, the appearance of bilirubin in urine and blood;
• serological tests - based on the detection of specific antibodies to alveococcus, using indirect haemagglutination, latex agglutination, enzyme immunoassay;
• skin-allergic test, called the Cazzoni reaction, is more indicated in case of liver echinococcosis, in the diagnosis of alveococcosis it is used to identify differences;
• instrumental studies allow to detect the violation of liver size, tissue structure, cystic formation with chambers inside the liver, ultrasound, computer and magnetic resonance tomography, radiography with contrasting bile ducts, radiographs of the liver on the background of pumping air into the abdominal cavity( pneumoperitoneum);
• biopsy of the node is performed with laparoscopy, if echinococcosis is completely excluded, since the procedure in this case threatens to colonize the abdominal cavity.

It is compulsory for the purpose of differential diagnosis to exclude:

• echinococcosis;
• cirrhosis of a different etiology;
• neoplasms of both malignant and benign character;
• polycystic liver disease;
• hemangioma.

Treatment of

Treatment of alveococcosis is carried out under stationary conditions. The possibilities and methods depend on the stage in which the process of liver damage is located. Surgical methods - are shown with timely detection, absence of spread of defeat from the liver to neighboring organs and distant metastasis. Unfortunately, this radical treatment accounts for only 15% of cases. In an operative way, the cyst is removed together with the lobe of the liver or within the healthy tissues.

With incomplete removal, the goal is to reduce the compression of neighboring structures. In the remaining areas of the hepatic tissue, the active growth of parasites is attempted by circular solution dissection:

• Tripaflavin,
• timothy palmitic acid ester,
• 96% alcohol.

There is information about good results of treatment by cryodestruction( exposure to cold temperatures minus 196 degrees).

The use of antiparasitic drugs is indicated in the postoperative period and in cases when the surgical method can not be used. Therapy helps:

• delay the spread of alveococcus;
• limit the affected area;
• to avoid metastasis.

But complete destruction of the pathogen in the liver can not be achieved. The drug Albendazole, Mebendazole is used. Its dosage is calculated by the weight of the patient. Treatment is carried out long courses with interruptions.

is mandatory. The symptomatic remedies include:

• immunomodulators for activation of protective forces;
• diuretics;
• cardiac funds;
• antiallergic drugs.

Prognosis for Patients and Prevention

Prognosis for alveococcosis is worse than with echinococcosis. Mortality is high. Given the slow growth of patients with an established diagnosis against the background of treatment live 8-10 years. There are isolated cases - 20 years.

Prevention of infection includes:

• compliance with personal hygiene, thorough washing of hands after walking in the forest, communicating with animals, cutting hides and meat;
• measures for the destruction of rodents are particularly necessary in the suburban areas with the onset of spring, in hazardous areas they will help destroy the source of infection;
• in institutions where wild animals( zoos, reserves, circus) are used, there is a veterinarian who is obliged to monitor the nutrition and health of the animal.

If a person has suspected a possible infection with alveococcosis of the liver, then it is necessary to pass tests for serological tests. To do this, you should consult a doctor-infectiologist of your clinic.

Where the blood donation is decided jointly by the health and sanitary authorities on its territory. Perhaps send to the bacteriological laboratory of the Center for Sanitary and Epidemiological Surveillance. The infectiologist always works in close connection with the epidemiologist, so the blood can be taken to the polyclinic and taken to another institution for analysis.

Alveococcosis - remains a serious not only medical problem, it has to be solved by various controlling economic bodies. The experience of medicine has proved that treatment, including surgical methods, should be conducted in specialized institutions with trained personnel.