Echinococcosis .Echinococcosis .- Causes, Symptoms and Treatment .MF .
This parasitosis is ubiquitous in the world, it is increasingly the southern regions of the country or countries with well-developed animal husbandry.In Russia, the incidence of echinococcosis ranges from 1 to 4 cases per 100 thousand. Population.The main problem of late diagnosis of echinococcosis is due to low-intensity symptoms of the disease at an early stage.
Echinococcosis - a chronic parasitic disease that affects animals and humans, causing chain Echinococcus granulosis (echinococcus), characterized by lesions of the internal organs, usually the liver and lungs, with the formation and development of hydatid cysts of serious violations of the affected organs.
Geographical distribution of echinococcosis extensive.Disease covered many southern countries of the world, as well as the northern areas of the country livestock.Some of these include the southern European countries such as Bulgaria, Greece, Spain, Italy, Cyprus, many South American countries, such as Brazil, Argentin
Causes of echinococcosis echinococcosis Pathogen
disease is caused by the larval stage of the tapeworm Echinococcus granulosis.It is the smallest tapeworm, 2.5-8 mm in length (sometimes 9mm), has a scolex (head) with 4 suckers and hooks (hooks form two rows with a total of 50).Adult worms has a head, neck and 3-4 segment, which differ in the degree of maturity: first segments are immature - 1-2 pieces, then androgynous, and the final mature segment.It is a mature segment of the uterus contains eggs (of 400 to 600 pieces).Each egg contains hexacanth (6 tikryuchnuyu larva embryo).Oncospheres enough rack in the environment: withstand temperature extremes from -30 ° to + 35-40 °, in the surface layer of soil is stored up to several months at a temperature of from 12 to 25 °, however, destroys the oncosphere sunlight for several days.
Echinococcus and hexacanth
sources of infection
final boss - dogs, wolves, foxes, jackals, coyotes, lynx, lions.
Intermediate host - sheep, buffaloes, horses, pigs, squirrels, hares, man.The transmission of the placenta - from the mother to the fetus in the case of a primary infection.
Driving circulation parasitic infestation: final host (animal) - environment (where bowel movements are allocated to segments and hexacanth) - intermediate host (such as a person) or uninfected final boss.Man, as an intermediate host is a biological dead end (ie, does not release eggs and segments of helminth in the environment, therefore, is not a source of infection).
Echinococcosis, development cycle
mechanisms of infection ehinokookozom
main mechanism of human infection - nutritional, contact-household.Human infection occurs through contact with animal dander - the hosts of helminths (often dogs), while collecting berries and herbs, drinking water from contaminated sources, the consumption of fruit and vegetables contaminated with faeces of the definitive host (eg, dogs).
Susceptibility general, however, have a high risk persons in certain occupations or lifestyles associated with farming of animals (slaughterhouse workers, shepherds, tanners, hunters, and others).
Short tapeworm life cycle of animals: In the definitive host (dogs, wolves and other) - the germ enters the body by eating the internal organs of the intermediate host (hares, squirrels, pigs, etc.) contaminated with echinococcus.In the mucosa of the small intestine develops mature individuals, producing eggs.Segments with ripe eggs detached from the body and come out with the feces.They have mobility.The eggs are stored in the external environment for a long time depending on the conditions.Parasites adults about 5-6 months, sometimes up to 12 months.
Short cycle of tapeworm in humans: Oral eggs reach the intestine of the intermediate host (eg, human), where from hexacanth out embryo, which is absorbed into the blood and through the portal vein to the liver, and sometimes the lungs.Here comes the stage of larval development in the form of a single-chamber bladder (larvotsisty) with a diameter of 5 cm. The wall of the bladder consists of an outer and inner germ-chitin shells.The cavity is filled with liquid.Inside the parent bubble may form subsidiaries and grandchild bubbles.The total weight of the bubbles can reach several tens of kilograms, and 6-10 liters of fluid.The inner shell of the bubble formed brood capsules of inverted scoleces.Scolex can be separated from the capsule and float freely in the cyst fluid.
pathological effects in humans Echinococcus
The main effect due to the formation of specific hydatid cysts in any organ, but most often it is the liver (80%) and lung (20%).This may be as a single cyst or multiple hydatid disease.
1) sensitizing effect (allergic reaction of immediate or delayed type, and at break of cysts - up to anaphylactic shock);
2) mechanical action - cyst grow and leads to a significant disruption of the function of the affected organ, and later atrophy of the organ.The end result can be fibrosis in the lungs - pulmonary fibrosis.Cyst formation timing differ depending on the number and the initial state oncospheres human body.On average, since the invasion (swallowed hexacanth) to form a bubble structure of the larvae takes about 2 weeks, a few months (4.5-5 months) cyst has a diameter of 5 mm, and then increases with age.Large cysts to several liters in volume for decades formed (20 years or more).
Immunity in echinococcosis unstable, the possibility of reinfection.
Clinical forms and symptoms of echinococcosis
During helminthiasis distinguish several stages:
1) asymptomatic (since the invasion to the formation of small primary cysts);
2) the appearance of small complaints and symptoms of injury of an organ;
3) pronounced symptoms of the disease;
4) the development of infection complications.
Such grading is very conditional because of the slow development of the disease, slow the growth of cysts.
liver Echinococcosis (more)
Patients concerned about weakness, nausea, decreased appetite, vomiting, disturbance of a chair, an itchy rash, abdominal pain (right upper quadrant, epigastrium).When viewed from an increase in the size of the liver and spleen (hepatosplenomegaly).The cyst can be accessed by palpation, firm to the touch.If there is a secondary bacterial flora, the cyst abscesses, and clinically the patient is fever (fever), chills, pain in the abdomen.May develop liver abscess.When squeezing the cysts intra- or extrahepatic bile ducts may develop jaundice mechanical (or obstructive) character.First, dark urine, yellowing of the sclera starts clarified stool, then turn yellow skin.Jaundice is intense, often accompanied by pruritus.The general analysis of blood - an increase of white blood cells, eosinophilia (15-25%).
severe complications of liver echinococcosis - perforation (opening) hydatid cysts that clinically manifest rezchayshey pain, severe allergic reactions up to anaphylactic shock, in this case happens dissemination (distribution) of echinococcus throughout the body with the development of secondary multiple echinococcosis.
liver Echinococcosis Echinococcosis
For large cysts patients concerned about shortness of breath, chest pain, hemoptysis.Maybe chest deformity, shortening of percussion sounds, and respiratory depression.Maybe mediastinal shift.The process may involve the pleura with the development of exudative pleurisy (inflammation of the pleural effusion fluid).
symptoms vary A break cysts.If a breakthrough in the bronchi, the patient has a sharp cough, dyspnea, cyanosis, severe allergic reactions.Breakthrough cyst into the cavity of the pleura and pericardium leads to the development of anaphylactic shock with fatal outcome.
The KLA: leukocytosis with stab shift (increasing the ratio of band on segmented neutrophils), eosinophilia (15-25%).
Very rarely, but echinococcosis may affect other organs: spleen, kidneys, central nervous system .It
occurs when larvae drift into the systemic circulation.One of the most important signs - recurrent allergic reactions such as hives on the background of the emerging signs of defeat of a particular organ.
Echinococcosis right lung
For diagnosis of infection is important competently assembled epidemiological history (contact with animal patient, frequent visits to the forests, the meadows, the presence of close contact with animals - dogs, etc.).
Laboratory and instrumental diagnostics includes:
1) ultrasound of the abdominal cavity, CT, Ro-graphy light to detect single or multi cysts. When a cyst puncture their study inadmissible in order to avoid a fatal outcome for the patient.
Echinococcosis of the liver on ultrasound
2) serological blood tests patient in order to detect specific antibodies (used reaction RNIF, IHA, ELISA) with high specificity methods from 80 to 90%, andhigh sensitivity - 98%.The vast majority of patients with detected cysts and hydatid suspected their nature have specific antibodies to echinococcus in the blood.
3) helminthological research (sputum, duodenal contents, urine) in the case of a breakthrough cysts in the lumen of hollow organs to detect hooklet.
4) General clinical method s - complete blood count (leukocytosis, eosinophilia), biochemical studies (increase of ALT, AST, GGT, bilirubin due to direct fraction) and others.
main method of therapy:
1) surgical treatment (removal of hydatid cysts followed by reduction of affected organ function).The method used radical echinococcectomy (complete removal of the cyst with fibrous sheath) or cyst dissection, fluid removal, complete the processing chamber with special disinfectants, drainage, suturing tightly.Any opening of hydatid cyst should be done with great care in order to avoid re-contamination (insulation fabrics, to prevent its falling into the cavity - thoracic or abdominal).
2) If the operation is not possible because of the massive destruction, the antiparasitic treatment is performed.Appointed albendazole course of 3 weeks or a few months, the number of cycles up to 20 times.Intervals between 21-28 days.Efficiency ranges from 41 to 72% (average 25% of patients with recurrent).Alternative medicine - mebendazole for 15 to 24 months.Antiparasitic treatment is performed in the postoperative period for prevention of contamination, patients in endemic areas with the presence of antibodies to echinococcus, but the absence of cysts, with full instrumental examination.
3) Symptomatic therapy (antihistamines, gepatoprotektory, antitussives and other
depending on the symptoms).
1) Special veterinary measures in order to prevent infestation of animals (dogs deworming, observance of sanitary regulations in slaughterhouses).
2) Survey decreed individuals with hydatid disease (hunters, breeders, dog breeders, slaughterhouse workers, meat processing plants and other)
3) Individual prevention: limit contact with dogs, personal hygiene - washing hands, careful processing of vegetables, fruits, berries before eating, drinking water from reliable sources.
infectious disease doctor Bykov NI