Echinococcosis

Description:

Echinococcosis - the rare chronically proceeding parasitic disease resulting from impact on an organism of a larval form of tape Echinococcus granulosus helminth.

Echinococcosis has wide circulation around the world. Statistically the population and animals of the southern countries is most intensively struck: countries of South America (Uruguay, Paraguay, Argentina, Chile, Brazil), Australia and New Zealand, North Africa (Tunisia, Algeria, Morocco, Arab Republic of Egypt), Southern Europe (Italy, Greece, Cyprus, Turkey, Spain, Yugoslavia. Bulgaria, France), further - the southern part the USA, Japan, India, the former USSR. In process of advance from the South to the North the prevalence decreases. In the territory of the former Union an echinococcosis is widespread in those republics and areas where the livestock production is developed, mainly sheep breeding - the North Caucasus, Transcaucasia, Kazakhstan, Kyrgyzstan, Uzbekistan, Moldova (incidence of the population makes 1,37 - 3,85 on 100 000), in Russia - Bashkortostan, Tatarstan, the Stavropol, Krasnodar, Altai, Krasnoyarsk, Khabarovsk regions, the Volgograd, Samara, Rostov, Orenburg, Chelyabinsk, Tomsk, Omsk, Kamchatka, Magadan, Amur regions and Chukotka Autonomous Okrug.

In Ukraine an echinococcosis is registered in the southern areas more often - Odessa, Crimean, Kherson, Nikolaev, Donetsk, Zaporizhia, in the others - sporadic cases.

In the territory of Ukraine 2 types of the centers are registered: in a steppe southern zone the "sheep" strain, in Polesia and forest-steppe - preferential "pork" circulates. The prevalence of sheep in Odessa region made 32%, cattle - 20%, pigs - 9%.

Echinococcosis symptoms:

Distinguish four stages of an echinococcosis:
- the first – latent (initial asymptomatic), from the moment of an oncosphere invasion (penetration into an organism) before emergence of subjective signs;
- the second - slight, preferential subjective frustration;
- the third - sharply expressed objective symptoms and
- the fourth - complications.

Duration of a current of stages, considering the slow growth of an echinococcal cyst, it is difficult to establish. It is only possible to note that speed of increase of symptoms is connected with localization of an echinococcus. So, for example, the cyst developing in peripheral departments of a parenchyma of a liver for many years can not give any feelings if it develops near portal fissures, then, squeezing the hepatic courses, quickly enough causes obturatsionny jaundice, and squeezing a portal vein, leads to development of ascites.

Clinical manifestations at initial stages of a disease are usually poor, they come to light when the cyst reaches the considerable sizes or in connection with the arrangement will squeeze important body and will lead to disturbance of its function. The echinococcal cyst of internals (a liver, kidneys, a spleen, etc.) is usually distinguished when the tugoelastichesky tumor is probed, and damage of lungs, bones is defined on x-ray films in the form of cystous educations.

Liver echinococcosis meets more often. At an uncomplicated echinococcosis of a liver the growing cyst stretches the capsule of body, causing stupid, aching, is more rare - pristupoobrazny pains.

On A. V. Melnikov's classification, distinguish 3 stages of a current of an invasion.
The first - initial asymptomatic - from the moment of infection before manifestation of the first clinical signs of a disease. The second stage - emergence of symptoms of a disease: complaints of patients to weakness, decrease in working capacity, deterioration in appetite, nausea and vomiting sometimes disturbance of a chair. On this background there are feelings of pressure and weight in right hypochondrium, epigastriums, and sometimes acute, severe dull aches, the Liver at a palpation is increased is a little painful, at a superficial arrangement of a cyst - soft, elastic, at the beginning calcification - ligneous density. Squeezing of a portal or lower vena cava, and also squeezing inside - and extrahepatic bilious channels leads to development of obturatsionny jaundice.

The third stage - a stage of the expressed pathological changes and complications: development of abscess, a possible rupture of a cyst with fever with oznoba, pains in an upper half of a stomach.

In a gemogramma - a leukocytosis with band shift, the eosinophilia is possible.

The rupture of a cyst - the heaviest complication of an echinococcosis happens at a bruise, falling, the sharp movement, a strong tussive push. Clinically perforation of a cyst can be shown by a complex of allergic reactions up to development of allergic shock. Dissimination of echinococcal cysts is especially dangerous.

Echinococcosis of lungs - manifestation of an invasion, the second for frequency, can simulate any disease of lungs of other etiology.

The first stage - a stage of not opened echinococcal cyst - is connected with growth of a bubble, a prelum of tissue of lung, vessels, bronchial tubes, involvement of a pleura. Patients are disturbed by an asthma, a pneumorrhagia, thorax pains, a severe cough, especially at night, in the beginning dry, then passing in wet with a mucopurulent phlegm. Visually - deformation of a thorax, a smoothness of intercostal spaces. Perkutorno - obtusion of a sound, auskultativno - weakening of breath, a pleural rub, etc.

The second stage is connected with opening of a cyst. At break in a bronchial tube the severe cough, suffocation, cyanosis, heavy allergic reactions, development of aspiration pneumonia develops (more often). At break in a pleura, a pericardium there can come anaflaktichesky shock and sudden death.

In cases of an echinococcosis of other bodies (a spleen, kidneys, bones, muscles) the symptoms simulating tumoral process prevail.

Important general symptoms of an echinococcosis are periodically developing signs of allergic reaction (a small tortoiseshell, etc.) that is usually connected with absorption of echinococcal liquid at anguishes of a cover of a cyst or as a result of operation. For an echinococcosis as, however, and for other helminthic diseases, the eosinophilia reaching 10-25% is characteristic.

Dangerous complications of an echinococcal cyst are suppuration or a gap it with planting of abdominal, pleural or any other cavity.

Echinococcosis reasons:

The causative agent of echinococcosis of the person is the larval stage of a tapeworm of an echinococcus - Echinococcus granulosus.

Puberal form of an echinococcus - a small cestode 2,5 - 5,4 mm long, 0,25 - 0,8 mm wide. It consists of a pear-shaped scolex, a neck and 3 - 4 joints.

The scolex is supplied with four suckers and a crown from two rows крючьев (28 - 50).

The scolex is followed by a short neck and joints, the first two - unripe, the third hermaphroditic and the fourth - mature. The mature joint (length of 1,27 - 3,17 mm) is filled with the stretched uterus representing a wide longitudinal trunk with side protrusions. The uterus is filled by the eggs (400 - 600 pieces) which are not differing on the structure from eggs of the bull and pork tapeworms (тениид) containing inside a shestikryuchny oncosphere.

The puberal form - a tapeworm of an echinococcus - parasitizes only at animals: dogs, wolves, jackals, foxes who are final owners. The larval stage - an echinococcal cyst - parasitizes at intermediate owners - various herbivorous and omnivorous hoofs (sheep, goats, cattle, pigs, horses, etc.) and the person.

The echinococcal cyst represents a bubble of very complex structure. Outside it is surrounded with a layered cover (cuticle) which thickness sometimes reaches 5 mm. Under a multilayer kutikulyarny cover the thin internal embryonic (germinative) membrane which produces proliferous capsules with a scolex, affiliated bubbles lies, and also gives growth to a layered cover.

Proliferous capsules represent the small puzyrkovidny educations disseminated on an embryonic membrane and connected to it a thin leg. They have the same structure, as the main bubble, but with the return arrangement of covers (outside germinative, inside - layered). Each proliferous capsule contains the scolex attached to its wall screwed inside and having typically for tapeworms a structure. The bubble is filled with the liquid playing a role of a protective medium for proliferous capsules and a scolex.

In liquid there can be freely weighed, come off scolex and proliferous capsules, so-called gidatidozny sand.

The bubble gradually becomes covered by a connective tissue cover. Quite often such maternal cyst, in addition to above the listed elements, contains still the so-called affiliated bubbles having the same structure, and in them - grand bubbles.

Such cysts are observed at the person. Sometimes affiliated bubbles are formed not in a maternal cyst, and outside. Such bubbles call exogenous.

The echinococcal cysts which are formed at animals, as a rule, do not contain proliferous capsules and a scolex, call them atsefalotsist. This form does not occur at the person.

In sheep-breeding regions of the southern zone the circulation of an echinococcus goes according to the scheme: a sheep —› the sentry dogs accompanying a flock —› sheep.

In the western areas of intensive pig-breeding the circulation of an echinococcus goes according to the scheme: pigs —› dogs —› pigs. Lack of active motive function at joints of a "pork" strain reduces pollution of hair of dogs, soils, thereby limits conditions of infection of people and animals.

Intensity of transfer of an invasion is defined, first of all, by the number of sources of an invasion of final owners and amount of the invasive material emitted by them - oncospheres and joints.

Oncospheres transfer temperature from -30 °C to +38 °C, on the surface of the soil in a shadow at a temperature of 10 - 26 °C keep viability within a month, but in the sun at a temperature of 18 - 50 °C perish in 1-5 days. In a grass at a temperature of 14 - 28 °C they perish not earlier than in 1,5 months. Oncospheres well transfer the low temperature at which a row of years can remain, but are very unstable to drying.

Circulation of an invasion at echinococcosis is carried out according to the known scheme: an invasion source (final owners - carnivores) —› the external environment contaminated by oncospheres and joints of a parasite —› the intermediate owner (herbivorous, the omnivores infected with larvae) —› not infected final owner.

The person - the intermediate owner - is the biological deadlock.

At an echinococcosis of the person as the final owner the basic position is held by a dog. Dogs catch when eating meat garbage of slaughters, lethal platforms, kitchens, when feeding of seized properties by it from slaughters or bodies of the animals slaughtered at home struck with larvotsist. Infection of dogs is possible also when feeding of hunting products by it - the struck bodies or corpses of wild vegetarians.

Ways of infection of intermediate owners are also various, herbivorous farm animals catch at a proglatyvaniye of eggs, the helminth joints with a grass, hay, water contaminated by excrements of the infested dogs. Pigs, being koprofaga, catch, eating excrements of dogs. The main role in infection of the person through dirty hands is played by communication with the infested dogs, on wool and which language there can be eggs and joints of tapeworms of an echinococcus. Healthy animals can also give an invasion to the person as mechanical carriers of eggs which their wool, language becomes soiled at a licking of the infected dog.

Infection of the person at the use is not excluded food of dirty vegetables, berries, the fruit contaminated by excrements of the dogs containing oncospheres.

The person can catch also from wild carnivorous during hunting during the cutting of skins, production of fur clothes, and also at consumption of dirty wild-growing berries, water drink from natural reservoirs.

In sheep-breeding areas where circulation of the activator happens generally between dogs and sheep, the shepherds, shepherds accompanying flocks and also shearers of hair of sheep and members from families treat risk groups.

Treatment of the Echinococcosis:

Extraction of an echinococcus is possible only in the operational way. There are several methods of operation:
1) a radical ekhinokokkektomiya, i.e. full removal of an echinococcal cyst together with its fibrous cover,
2) opening of a cyst with removal of liquid, all affiliated bubbles and a chitinous cover with wiping of the formed cavity disinfecting solution of formalin and packing, drainage or its mending tightly.

When opening an echinococcal cyst special attention is paid on isolation of perigastriums and fabrics from echinococcal liquid as its hit in a cavity (belly, chest, etc.) or on walls of a wound can lead to planting.