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Hydatidous echinococcosis: an overview
Last reviewed: 23.04.2024
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Echinococcosis is a chronic course of biogelmintosis caused by the parasitization of larvae of cestodes of the genus Echinococcus in humans.
ICD-10 codes
- Q67. Echinococcosis.
- B67.8. Echinococcosis of liver, unspecified.
- B67.9. Echinococcosis of other organs and unspecified.
Echinococcosis hydatidosis (single-chamber echinococcosis, echinococcosis cystic, Latin echinococcosis, English echinococcus disease) - chronic zoonotic biohelminthosis with fecal-oral mechanism of transmission of the pathogen, characterized by the formation of parasitic cysts in the liver, less often in the lungs and other organs.
ICD-10 codes
- B67.0. Liver invasion caused by Echinococcus granulosus.
- B67.1. Invasion of the lung, caused by Echinococcus granulosus.
- B67.2. Bone invasion caused by Echinococcus granulosus.
- B67.3. Invasion of another site and multiple echinococcosis caused by Echinococcus granulosus.
- B67.4. Invasion caused by Echinococcus granulosus, unspecified.
Epidemiology of hydatidosis echinococcosis
The source of E. Granulosus for humans is often home dogs, less often - wild animals (wolves, jackals, etc.). The main transmission factor - the hands, polluted oncospheres of echinococcus, which in abundance are on the wool of the invaded dogs. Infection of a person can also occur when collecting berries and herbs, drinking water from sources contaminated with eggs of helminth. Disease hydatidosis echinococcosis is more common in certain professional groups: workers of slaughterhouses, shepherds, tanners, hunters, members of their families, especially children. There are different strains of echinococci, adapted to different intermediate and final hosts. To some strains in humans, in particular to the "horse strain" common in countries of Western Europe and Great Britain, a certain resistance is noted, while the "sheep strain" is highly pathogenic to humans.
Hydatidid echinococcosis occurs on all continents. Most often it is registered in countries with pastoral pastoralism, especially where dogs are traditionally used to protect sheep and cattle. In the southern hemisphere, the intensity of the lesion is particularly high. In the CIS countries, echinococcosis is common in regions with developed livestock breeding, mainly sheep breeding: in Transcaucasia, Kazakhstan and other countries of Central Asia, Ukraine, Moldova.
[What causes hydatidic echinococcosis?
Hydatid hydatid Echinococcus granulosus is of the type Plathelminthes, class Cestoda. the Taeniidae family . Sexually mature E. Granulosus is a belt helminth of white color 3-5 mm in length. It consists of a head with four suckers and a double crown of hooks, from the cervix and 2-6 segments. The last segment is filled with a uterus containing eggs (oncospheres), which possess invasive ability and do not need ripening in the environment. Sexually mature helminth parasitizes in the small intestine of the final host - carnivorous animals (dogs, wolves, lynxes, cats, etc.). Mature segments with feces get into the environment. Eggs are highly resistant in the external environment, in winter they remain viable up to 6 months.
Pathogenesis of hydatidosis echinococcosis
Because of the hematogenous pathway, the oncospheres of echinococcus can be entered into any organ, but most often echinococcal cysts are located in the liver (30-75%) and lungs (15-20%), much less often in the central nervous system (2-3%), spleen , pancreas, heart, in tubular bones and kidneys (up to 1%). The transformation of the oncosphere into a larvocyst in an invaded person lasts about 5 months; during this time it reaches a diameter of 5-20 mm. The pathological effect of echinococcus is due to mechanical and sensitizing factors. In most patients, the only organ is affected by a single solitary cyst, but multiple echinococcosis can develop.
Symptoms of hydatidosis of echinococcosis
There are the following stages of hydatidid echinococcosis: preclinical, uncomplicated and the stage of complications.
With the most common lesion - liver echinococcosis - the first symptoms of hydatidosis echinococcosis usually appear in a few years and even decades after infection. Often, echinococcus is diagnosed accidentally (with planned fluorography, ultrasound) or with a targeted examination of the population in the outbreaks. Gadatidosis echinococcosis is more often detected in middle-aged people. Symptoms of liver hydatidosis echinococcosis in uncomplicated cases: decreased performance, general weakness, dyspeptic disorders, headaches, sometimes allergic manifestations - skin rashes, itching, eosinophilia in the blood. The liver at palpation is enlarged, dense (with localization of the bladder in the depth of the parenchyma) or soft, elastic (with a superficial arrangement of cysts), with calcification - woody-dense.
How is hydatidosis caused by echinococcosis?
Assuming echinococcosis allows symptoms (a tumor-like, slowly growing formation in the liver, lungs or other organs) and epidemiological data.
Seroimmunological methods (ELISA, RIGA, RLA) give positive results in 90% of cases and more with liver damage, with echinococcosis of lungs, effectiveness is lower (60%). Antibody titers in the early period of invasion, with unopened or medically untreated cysts may be low or the reactions give negative results. An intradermal test with an echinococcal antigen (known as the Casoni reaction) is not currently used due to the frequent development of allergic complications. Parasitologic diagnosis is possible with the breakthrough of echinococcal cysts into the lumen of hollow organs - then scolexes or individual parasite hooks can be found in sputum, duodenal contents, feces.
How is Hydatidid Echinococcosis Treated?
Mode and diet are determined by the nature of complications.
Chemotherapy is performed in cases of rupture of cysts, when there is a danger of seeding when the integrity of the cyst is compromised during surgery, and also in cases of multiple small cysts (not more than 3-5 cm) of the liver, lungs and other organs, in which surgical intervention is technically difficult. Anti-relapse treatment of hydatidosis echinococcosis is recommended after surgery, when it is impossible to exclude another localization of a small parasite.
How is hydatidosis prevented echinococcosis?
Echinococcosis hydatidosis can be prevented if one observes personal hygiene. Special caution is needed when keeping dogs in the house and caring for animals. Conducting scheduled dehelminthization of dogs. In places, unsuccessful for echinococcosis. Planned check-up of risk groups is necessary.
What is the prognosis of hydatidosis echinococcosis?
After a radical removal of echinococcal cysts, the prognosis is favorable; if surgical treatment is not possible - unfavorable.