Echinococcosis, what is it? Causes and treatment in humans

Echinococcosis is a kind of helminthic invasion, the causative agent of which are echinococci belonging to the group of tapeworms (cestodes).Pathology develops during the larval stage of the larval stage (oncosphere), and is found mainly in people living in South America and Europe, North Africa, New Zealand, Australia and other countries abroad.

In Russia, this disease is not particularly prevalent. Most often it can be found in the Volga region, Western Siberia, the Krasnodar region, the Far East. In echinococcus regions, the percentage of echinococcosis disease is between 5 and 10%.

The development of pathology is closely related to the breeding of livestock and other domestic animals. Echinococcosis is an extremely dangerous disease that can lead to the defeat of various internal organs, so it requires immediate medical intervention.

Mechanisms of infection with echinococcosis

The main ways of infection with echinococci is alimentary and contact-household. So, you can get infected by contact with the hair of pets or livestock. Most often, the carriers of these parasites are dogs, but infection can occur not only because of contact with them.

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For example, penetration of echinococci can occur with the use of unwashed fruits or vegetables, raw or poorly thermally processed meat, and even when harvesting. Drinking water from contaminated water can also lead to the development of echinococcosis.

Despite the fact that no one is insured against this type of helminthosis, most people are exposed to it, breeding animals, cattle, collecting berries, fruits, vegetables. Also under threat are tanners, shepherds, hunters, farm workers and slaughterhouses.

Etiology

The causative agent of the disease is the common echinococcus. Mature individuals of this tapeworm reach 7 mm in length and a head on which 4 suckers are located, as well as a double crown consisting of 35-40 hooks, a cervix and 2 to 6 joints.

At the larval stage, echinococcus continues to grow and develop in the human body. This process can take dozens of years, while a person over a long period of time may not even suspect of having a dangerous disease.

The main vectors of pathology are representatives of the Psov family. Adult individuals of echinococci are excreted along with the calves, after which they freely creep along the wool of their carrier. The intermediate hosts are sheep, cows, and goats. They become infected in case of eating dirty grass. As a result, a person also becomes a carrier of echinococcus during the drinking of milk and the use of products of animal origin - meat, cheese, sour cream.

Sexually mature individuals inhabit the mucous membranes of the small intestine of various fauna.

Pathogenesis of echinococcosis

Inhabits echinococcus in the intestine of a person. Under the influence of enzymes produced by the digestive organs, the shell in which the worm's larva is located is destroyed, and it crawls out. At the expense of the hooks on his body, the echinococcus is attached to the walls of the intestinal mucosa, and then, along with the blood flow, is transferred to the portal system.

Most oncospheres concentrate in the hepatic tissues, although sometimes they penetrate through the hollow vein into the right heart departments, after which they enter the small circle of the circulation. Together with the blood, the larvae reach the lungs, from where they penetrate into the great circle of blood circulation. Further they can get into the tissues of any organs - spleen, brain, kidney, musculature, etc. As a result, there is development of echinococcosis of the liver, lungs, kidneys, etc. After penetration and subsidence of the larva in the tissues of the affected organ begins the so-called bubbly stage of development of pathology. The bubble, in which the embryo of the echinococcus is located, looks like a cyst with a two-layered shell. It consists of an embryonic and a chitinous layer.

Over time, the cyst begins to increase in size - about a millimeter per month. If the disease is not detected in time, over the years the cyst can acquire huge dimensions. Inside it contains a liquid that has a whitish hue or is completely transparent. Smaller bubbles and scolexes float in it. Small (daughter) vesicles are able to form from outside the shell of the bladder and reach a quantity of 1000.

Specific symptoms of echinococcosis are manifested under the irritating effect of cysts on the mucous membranes of the organs in which they are located. During the entire period of its life, echinococci release toxic substances, which gradually lead to sensitization of the body. As a consequence, allergic reactions develop and signs of intoxication of the organism appear.

In especially severe cases, even anaphylactic shock is possible, since in the absence of treatment, the lining of echinococcus larvae ruptures, and its contents flow into the abdominal or pleural cavity. But even if this does not happen, the cyst will gradually increase, exerting pressure on the tissues of the organ, on the mucous membranes of which it is located. This will entail a violation of its functions, which poses a serious threat to human health.

Sometimes the cyst is able to go into the stage of abscessing, when purulent contents gradually begin to accumulate in it. Very rarely self-destructive echinococci, which leads to complete recovery of the patient without medical intervention.

Clinical forms and symptoms of echinococcosis

The course of this type of helminthiasis is divided into several stages:

Asymptomatic, which lasts from the moment of infection and to the formation of small cysts.
Easy, when the first alarming symptoms only begin to manifest. In this case, a person complains of discomfort or a little palpable pain in the area of the helminthic organ.
At the stage of moderate severity, the clinical picture of the disease manifests itself quite sharply, therefore it is impossible to ignore it.
In severe cases of echinococcosis, various complications of the disease develop.

However, the division of pathology at the stage is conditional, since the formation and growth of cysts - the process is extremely slow, taking a lot of time.

Echinococcosis of bile ducts

Often the disease affects the gallbladder, and after a while the pathological process involves the biliary tract. Cyst of large size is capable of bursting into the cavity of the bile duct, resulting in the development of hepatic colic. This process is accompanied by bouts:

nausea;
vomiting;
intense pain in the right upper quadrant.

In addition, echinococcosis of the gallbladder often leads to the development of jaundice, a violation of the stool, and can also cause exacerbation of chronic cholangitis with such concomitant symptoms as fever and chills. Possible blockage of the bile ducts, accompanied by symptoms of cholangitis and cholecystitis. If there has been a development of septic cholangitis or hepatitis, or in the presence of multiple lesions hepatic tissues the prognosis of the further course of echinococcosis of this localization is extremely unfavorable.

The disease often ends in a lethal outcome, so treatment is mainly performed through surgical intervention. To restore the normal outflow of bile, the affected bile duct is opened, and all cysts are excised. After this, the duct is drained.

At a high risk of death, cholecystectomy can be performed, in parallel with which the hepatic cyst is often removed. Less often do drainage of the cyst, which helps restore the outflow of bile.

Echinococcosis of the liver

Also the widespread localization of echinococcal oncospheres, which are entered into the liver with blood flow. They can penetrate the hepatic parenchyma, bile ducts or abdominal cavity. Localized cysts in the right lobe of the liver.

The first symptom is a feeling of pressure and discomfort in the epigastrium and in the right hypochondrium. When suppuration of the bladder causes the appearance of symptoms of liver abscess, the opening of which can lead to purulent pleurisy or peritonitis. If the abscess breaks into the biliary tract, it may develop purulent cholangitis.

When the infected bladder ruptures, severe allergic reactions occur. Sometimes there is an anaphylactic shock. In the early stages, cysts are treated with medications.

Echinococcosis of the kidney

The larva of echinococcus is entered into the renal tissues with arterial blood flow. The site of its localization is mainly cortical substance, where it is attached and forms an echinococcal cyst. The left kidney most often suffers.

Echinococcal renal cyst happens:

closed, when the integrity of the kidney wall is not disturbed;
pseudo-closed;
Prolabiruyuschey, which affects the renal calyx and is washed with urine;
open, affecting the cup-and-pelvis system, and causing development of echinococci.

With the defeat of the kidneys of the echinococcal cyst, the organs move and deform them. Renal calyxes and pelvis widen, the destruction (atrophy) of the parenchyma occurs.

As a result of renal echinococcosis, the patient begins to feel a general malaise, symptoms of intoxication of the body occur. The patient quickly becomes tired, feels constant weakness and fatigue, he loses his appetite and, as a consequence, weight.

As the growth of the echinococcal cyst, the following ailments occur:

constant dull pain in the hypochondrium from the side of the affected kidney (pain syndrome can irradiate in the lower back);
development of renal colic;
subfebrile or febrile fever;
the occurrence of skin itching without rash;
eosinophilia of the blood.

When the daughter echinococcal cysts leave together with urine, there is an attack of renal colic. In the excreted urine, blood admixtures (hematuria) are visible, possibly exacerbation of pyelonephritis. Dysuria or urinary retention may develop, and spontaneous dissection of the abscess into the renal tissues may lead to leukocyturia. With a closed form of the disease, changes in the composition of urine are not so common. But, nevertheless, an occurrence is possible:

hematuria;
leukocyturia;
proteinuria (an admixture of protein in the urine);
cylinderuria.

With an open form, pyuria is most common, and hematuria is more common. Urine clouding, it contains white flakes and scraps of dead kidney tissues. In 20% of patients there is an increase in the level of eosinophils in the blood, and in a third of cases there is a moderate leukocytosis, and in 65% of cases there is an increase in ESR.

During the cystoscopy, structural changes in the mucous membranes of the bladder are found. When echinococcus is noted the presence of daughter, freely floating blisters. When they die, the cyst acquires a homogeneous or pinnate shape.

Treatment of this type of echinococcosis requires surgical intervention. Cysts are removed by echinococcectomy, kidney resection or nephrectomy. The prognosis of recovery depends on the severity of the symptoms and the prevalence of the pathological process.

Echinococcosis of the brain

Brain echinococcosis is manifested through the occurrence of the following anomalies:

formation of seals, consisting of connective tissues of the brain around the echinococcus;
development of the inflammatory shaft;
the occurrence of foci of softening and hemorrhages in the brain tissue.

In addition, the inflammatory process can cause changes in the meninges at the site of the echinococcus bladder, the diameter of which can sometimes reach up to 3 cm.

Echinococcosis of the brain is accompanied by pronounced symptoms, which are similar to the signs of the tumor of the GM. Among the most common signs of pathology, it should be noted the development of hypertension syndrome, accompanied by headaches, nausea, vertigo, attacks of epilepsy.

When alveolar echinococcosis develops cortical epileptic seizures that promote the development of tetraparesis. Some patients experience disorders of the psycho-emotional state, which leads to dementia, delirium and depression.

Echinococcosis of the brain causes the occurrence of eosinophilia or pleocytosis. Such deviations are found in the study of cerebral fluid (CSF). Intracerebral echinococcosis is prone to rapid progression and increased symptomatology, and also leads to the development of hypertensive syndrome. With multi-chamber echinococcosis of the GM, frequent relapses occur.

If the disease provoked the formation of a solitary cyst, it is removed surgically.

Echinococcosis of the lungs

When the cyst located in the lung begins to increase, the patient develops a cough, sometimes with an admixture of blood. The patient suffers from chest pain, dyspnea. If the cyst is large, the thorax begins to deform, which leads to the bulging of the intercostal spaces.

With the breakthrough of the cyst into the bronchial lumens, there is a productive paroxysmal cough. During coughing, copious quantities of sputum of light shade and medium density are released. Sometimes in the mucus to be separated, an admixture of blood can be traced, the patient's breathing becomes difficult, he lacks air, cyanosis develops.

Sometimes the cyst bursts into the pleural cavity. Then the patient complains of severe acute pain in the chest, chills, trembling in the body, heat. In extremely severe cases, anaphylactic shock develops. In the pleural cavity begins to accumulate fluid, which causes shortness of breath, frequent attacks of cough.

In the early stages of the drug therapy is carried out, at late stages - surgical intervention is performed. If treatment is started in a timely manner, the recovery prognosis is favorable.

Diagnostics

Since the symptomology of pathology does not have specific manifestations, the patient should be carefully examined, based on his complaints. When suspected of echinococcosis, the following diagnostic measures are carried out:

UAC for detecting the level of eosinophils and accelerating ESR.
Biochemical blood test shows the correlation of blood proteins, reveals the level of albumin and prothrombin (reduced with echinococcosis), as well as gamma globulins (the level is increased).
Bakposev urine and sputum for the detection of pathogenic microflora, in particular, echinococcus.
Cassoni's test is a kind of allergotest, the positive result of which indicates the presence of an echinococcal infection.
Immunological tests - RNGA, ELISA, RFA, with the help of which the antigens of echinococcus and antibodies to it are determined.
Ultrasound, with the help of which echinococcosis of the liver and kidneys is detected.
CT scan.
MRI.
Radiography.

Often, pathology is detected accidentally, during preventive fluorography or instrumental research for the presence of other diseases.

Methods of treatment of echinococcosis

The main methods of therapy are:

Operative intervention aimed at removing cysts and restoring the functions of the affected organ. Sometimes complete removal of the cyst along with its fibrous membrane. With a relatively light disease, the bladder is opened, the contents removed and treated with antiseptic drugs. After that, the place of the cut is carefully sewn.
If it is impossible to perform the operation, antiparasitic therapy is performed. Use the drug Albendazole, the course of which lasts from 3 weeks to several months. To achieve the expected results, 20 treatment cycles are performed at intervals of 3-4 weeks. If necessary, the drug can be replaced with Mebendazole course from 15 months to 2 years. Antiparasitic therapy is also performed after surgery.
Symptomatic treatment with antiallergic drugs, hepatoprotectors, antitussive drugs, etc.

Prophylaxis of echinococcosis

For the prevention of echinococcosis it is necessary:

Observation at the doctor and the passage of preventive examinations for 10 years.
Immediate hospitalization of people working in the agrarian sphere, in the presence of symptoms of helminthic invasion.
Accounting and thorough examination of domestic dogs for the presence of helminthiasis. If you identify these, conduct the necessary therapy.
Careful regulation of populations of stray dogs.
Quality control of meat and meat products.

After the course of therapy the patient should be on a dispensary record. The doctor must be visited once every 24 months. The medical examination lasts from 8 to 10 years.