Echinococcosis is a type of helminthic invasion, the causative agent of which is echinococcus, belonging to the group of tapeworms (cestodes). Pathology develops during the course of the larval stage (oncosphere), and occurs mainly in people living in South America and Europe, North Africa, New Zealand, Australia and other foreign countries.
In Russia, this disease has no particular prevalence. Most often it can be found in the Volga region, Western Siberia, the Krasnodar region, in the Far East. In the regions where the echinococcus dwells, the percentage of echinococcosis 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 echinococcus is alimentary and contact-household. So, you can become infected through contact with the hair of domestic animals or livestock. Most often, these parasite carriers are dogs, but infection can occur not only because of contact with them.
For example, the penetration of echinococcus can occur when eating unwashed fruits or vegetables, raw or poorly heat-treated meat, and even when harvesting. Drinking water from polluted water can also lead to the development of echinococcosis.
Despite the fact that no one is insured against this type of helminthiasis, people who breed animals, cattle are most susceptible to it, they collect berries, fruits and vegetables. Also tanners, shepherds, hunters, farm workers and slaughterhouses are at risk.
Echinococcus vulgaris is the causative agent of the disease. Mature individuals of this tapeworm reach 7 mm in length and the head, on which 4 suckers are located, as well as a double crown consisting of 35-40 hooks, a neck and from 2 to 6 segments.
At the larval stage, the echinococcus continues to grow and develop in the human body. This process can take dozens of years, while the person over a long period of time may not be aware of the presence of a dangerous disease.
The main carriers of pathology are representatives of the Canine family. Adults of echinococcus are excreted along with fecal masses, after which they freely creep away in the hair of their wearer. The intermediate hosts are sheep, cows, goats. They become infected if they eat dirty grass. As a result, a person also becomes a carrier of echinococcus when drinking milk and eating animal products - meat, cheese, sour cream.
Mature individuals inhabit the mucous membranes of the small intestine of various representatives of the fauna.
Pathogenesis of echinococcosis
It inhabits the echinococcus in the human intestine. Under the influence of enzymes produced by the digestive organs, the shell in which the worm larvae is destroyed, and it crawls out. Due to the hooks on his body, echinococcus is attached to the walls of the intestinal mucosa, after which, together with the bloodstream, is transferred to the portal system.
Most of the oncospheres are concentrated in the liver tissues, although sometimes they penetrate the right heart regions through the vena cava, after which they enter the pulmonary circulation. Together with the blood, the larvae reach the lungs, from where they penetrate into the great circulation. Then they can get into the tissues of any organs - the spleen, brain, kidney, muscles, etc. As a result, the development of echinococcosis of the liver, lungs, kidneys, etc. occurs. . The bubble, in which the germ of an echinococcus is located, resembles a cyst with a two-layer membrane. It consists of the embryonic and chitinous layer.
Over time, the cyst begins to increase in size - about a millimeter per month. If the disease is not detected in a timely manner, over the years, a cyst can become enormous. Inside it contains a liquid that has a whitish shade or completely transparent. In it bubbles of the smaller sizes and a scolex float. Small (daughter) bubbles are able to form from the outside of the bubble shell and reach a number of 1000.
The specific symptoms of echinococcosis manifest themselves under the irritating effect of cysts on the mucous membranes of the organs in which they are located. During the entire period of their vital activity, echinococcus secrete toxic substances, which gradually lead to sensitization of the organism. As a result, allergic reactions develop and signs of intoxication appear.
In severe cases, even anaphylactic shock is possible, since, if left untreated, the membrane with the echinococcus larvae is broken, and its contents flow into the abdominal or pleural cavity. But even if this does not happen, the cyst will gradually grow, 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 represents a serious threat to human health.
Sometimes a cyst is able to pass into the stage of abscess formation, when the purulent contents gradually accumulate in it. It is rarely possible self-destruction of echinococcus, which leads to full 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 until the formation of a cyst of small size.
- Easy, when the first disturbing symptoms are just beginning to manifest. At the same time, a person complains of discomfort or a little tangible pain in the area of the organ affected by helminthiasis.
- At the stage of moderate severity, the clinical picture of the disease appears quite sharply, so it becomes impossible to ignore it.
- In severe echinococcosis, various complications of the disease develop.
However, the division of pathology into stages is conditional, since the formation and growth of cysts is an extremely slow process that takes a lot of time.
Echinococcosis of biliary tract
Often, the disease affects the gallbladder, and after some time the biliary tract is involved in the pathological process. A large-sized cyst is able to rupture in the bile duct cavity, as a result of which hepatic colic develops. This process is accompanied by attacks:
- intense pain in the right hypochondrium.
In addition, echinococcosis of the gallbladder often leads to the development of jaundice, impaired stool, and can also cause an exacerbation of chronic cholangitis with associated symptoms such as fever and chills. Possible obstruction of the bile ducts, accompanied by symptoms of cholangitis and cholecystitis. If there was a development of septic cholangitis or hepatitis, or in the presence of multiple lesions of the liver tissues, the prognosis of the further course of echinococcosis of this localization is extremely unfavorable.
The disease is often fatal, so treatment is mainly carried out through surgical intervention. To restore the normal flow of bile, the affected bile duct is opened, and all cysts are excised. After this is the drainage of the duct.
At high risk of death, cholecystectomy can be performed, in parallel with which the removal of a hepatic cyst is often performed. Rarely do drainage cysts, which helps to restore the flow of bile.
Also common localization of echinococcal oncospheres, which are entered into the liver with the bloodstream. They can enter the hepatic parenchyma, bile ducts, or the 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 symptoms of liver abscess, the opening of which can lead to purulent pleurisy or peritonitis. If an abscess breaks into the biliary tract, purulent cholangitis may develop.
When you break an infected bladder, severe allergic reactions occur. Sometimes anaphylactic shock occurs. In the early stages, cysts are treated with the help of medications.
The larva of echinococcus is introduced into the renal tissues with arterial blood flow. The site of its localization is mainly the cortical substance, where it attaches and forms an echinococcal cyst. Most often, the left kidney suffers.
Echinococcal renal cyst is:
- closed, when the integrity of the kidney wall is not broken;
- prolapse, which affects the renal calyx and is washed by urine;
- an open, touching pan-pelvis system, and echinococuria causing development.
With the defeat of the kidneys with an echinococcal cyst, the organs are displaced and their deformity occurs. The renal calyx and pelvis are dilated, destruction of the parenchyma occurs (atrophy).
Due to the renal echinococcosis, the patient begins to feel general malaise, symptoms of intoxication appear. The patient quickly gets tired, feels constant weakness and fatigue, he loses his appetite and, as a result, weight.
As the hydatid cyst grows, the following discomforts occur:
- constant dull pain in the hypochondrium of the affected kidney (pain may radiate to the lower back);
- development of renal colic;
- low-grade or febrile fever;
- itching without rash;
- blood eosinophilia.
When the daughter echinococcal cysts depart with the urine, an attack of renal colic occurs. In the excreted urine, blood impurities are visible (hematuria), pyelonephritis may worsen. Dysuria or urinary retention may develop, and with spontaneous opening of the abscess in the renal tissues - leukocyturia. In the closed form of the disease, changes in the composition of the urine are not so common. But, nevertheless, the occurrence is possible:
- proteinuria (protein impurity in the urine);
In the open form, pyuria is most common, less commonly hematuria. Urin grows turbid, it contains white flakes and scraps of dead kidney tissue. In 20% of patients there is an increase in the level of eosinophils in the blood, and in a third of cases moderate leukocytosis occurs, and in 65% of cases an increase in ESR occurs.
During cystoscopy, structural changes in the mucous membranes of the bladder are detected. In echinococuria, the presence of affiliated, freely floating bubbles is noted. When they die, the cyst acquires a homogeneous or pinnate form.
Treatment of this type of echinococcosis requires surgical intervention. Cysts are removed through echinococcectomy, kidney resection, or nephrectomy. The prognosis for recovery depends on the severity of the symptoms and the prevalence of the pathological process.
Cerebral echinococcosis is manifested through the occurrence of the following anomalies:
- formation of seals consisting of connective tissue of the brain around the echinococcus;
- development of the inflammatory wall;
- the emergence of foci of softening and hemorrhage in the brain tissue.
In addition, the inflammatory process can cause changes in the meninges at the location of the echinococcal bladder, whose diameter can sometimes reach 3 cm.
Echinococcosis of the brain is accompanied by pronounced symptoms that have similarities with signs of a GM tumor. Among the most common signs of pathology should be noted the development of hypertensive syndrome, accompanied by headaches, nausea, vertigo, epileptic seizures.
When alveolar echinococcosis occurs, the development of cortical epileptic seizures, contributing to the development of tetraparesis. In some patients, there are violations of the psycho-emotional state, which leads to dementia, delirium and depression.
Echinococcosis of the brain leads to 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 build-up of symptoms, and also leads to the development of hypertensive syndrome. With multi-chamber echinococcosis of the GM, frequent recurrences occur.
If the disease triggers the formation of a solitary cyst, it is surgically removed.
When a cyst located in the lung begins to grow, the patient develops a cough, sometimes with blood. The patient suffers from chest pain, shortness of breath. If the cyst is large, the rib cage begins to deform, which leads to bulging of the intercostal spaces.
When a cyst breaks through into the bronchial lumens, a productive paroxysmal cough occurs. During coughing, copious amounts of sputum of light color and medium density are released. Sometimes in the discharge of mucus can be traced blood, the patient's breathing becomes difficult, he does not have enough air, cyanosis develops.
Sometimes a cyst breaks into the pleural cavity. Then the patient complains of severe acute chest pain, chills, trembling through the body, high fever. In extremely severe cases, anaphylactic shock develops. In the pleural cavity, fluid begins to accumulate, causing shortness of breath, frequent coughing attacks.
In the early stages, medical therapy is carried out, in the later stages, surgery is performed. If treatment is started in a timely manner, the prognosis for recovery is favorable.
Since the symptomatology of the pathology does not have specific manifestations, the patient should be carefully examined based on his complaints. If echinococcosis is suspected, the following diagnostic measures are performed:
- KLA to identify the level of eosinophils and accelerated ESR.
- Biochemical analysis of blood shows the ratio of blood proteins, reveals the level of albumin and prothrombin (reduced with echinococcosis), as well as gamma globulins (increased level).
- Bacteri urine and sputum to identify pathogenic microflora, in particular, echinococcus.
- Kasoni's test is a type of allergic test, a positive result of which indicates the presence of an echinococcal infection.
- Immunological tests - RNA, ELISA, XRF, by which the echinococcus antigens and its antibodies are determined.
- Ultrasound, with the help of which echinococcosis of the liver and kidneys is detected.
- CT scan.
Often, pathology is detected by chance, during prophylactic fluorography or instrumental studies for the presence of other diseases.
Ways to treat echinococcosis
The main methods of therapy are:
- Surgical intervention aimed at removing cysts and restoring the functions of the affected organ. Sometimes a complete removal of a cyst is performed along with its fibrous membrane.With a relatively easy course of the disease, the bladder is opened, its contents are removed and antiseptic preparations are processed. After this, the incision site is carefully sewn.
- If it is impossible to perform the operation, antiparasitic therapy is carried out. Use the drug Albendazole, the course of which lasts from 3 weeks to several months. To achieve the expected results, 20 treatment cycles are conducted at intervals of 3–4 weeks. If necessary, the drug can be replaced by Mebendazole course from 15 months to 2 years. Antiparasitic therapy is also carried out after surgery.
- Symptomatic treatment with the use of antiallergic drugs, hepatoprotectors, antitussive drugs, etc.
For the prevention of echinococcosis, you must:
- Supervision at the doctor and passing of preventive examinations for 10 years.
- Immediate hospitalization of people working in the agrarian sector, in the presence of symptoms of helminthic invasion.
- Accounting and thorough examination of domestic dogs for the presence of helminthiasis. In identifying those conduct the necessary therapy.
- Careful regulation of stray dog populations.
- Quality control of meat and meat products.
After completing the course of therapy, the patient should be in the dispensary. The doctor must be visited once in 24 months. Clinical examination lasts from 8 to 10 years.