Echinococcosis is a helminthiasis caused by the larval stage of the tapeworm Echinococcus granulosus.
Content
The structure of the causative agent of the disease
Echinococcus consists of a head with 4 suckers and a proboscis with 2 corollas of hooks. Behind the head there is a neck and three segments. The first segment is immature, the second is hermaphroditic, the third is mature.
The hermaphrodite segment contains 400-800 fertilized eggs.
Echinococcus development cycle
More details about the structure and life cycle of Echinococcus are written in the article “ Echinococcus - life cycle, structure, description .”
Reaching maturity by Echinococcus involves changing two hosts.
The definitive host of the worm is dogs and all representatives of the canine family (wolves, jackals, etc.). Echinococcus lives in the final host for 5-6 months.
New segments constantly bud from the neck of the worm, and the rear mature ones break off and exit into the external environment either with feces or actively crawling out through the anus. Crawling over the dog's body, they contaminate the animal's fur with eggs released from the uterus.
The eggs enter the body of the intermediate host (a wide range of mammals, including humans) through the mouth. In the small intestine, the oncosphere emerges from the eggs and, with the help of hooks, penetrates the blood vessels of the intestine and then through the portal vein into the liver. Most of them linger there.
Some of the oncospheres are carried throughout the body in the blood. They can get into any organ - the brain, lungs, spleen, kidneys, bones.
Definitive hosts become infected by eating organs of an intermediate host that contain echinococcal blisters.
In the small intestine of the final host (for example, a dog) echinococci begin to develop.
Echinococcosis
Echinococcosis (ICD-10 code - B67) is a helminthiasis caused by the larval stage of the tapeworm Echinococcus granulosus, characterized by a chronic course and development mainly in the liver, less often in the lungs and other organs.
Prevalence in the world
Echinococcosis is distributed in the world with varying frequency. The most common incidence is observed in Argentina, Uruguay, Brazil, Chile, Paraguay, Peru, Mongolia, Pakistan, Afghanistan, Iran. High epidemic areas are Tunisia, Algeria, Morocco, Kenya, Somalia, Ethiopia, Sudan, Egypt, Libya, Yugoslavia, Bulgaria, Greece, Italy, Turkey, Cyprus, Spain, Syria.
In Russia, the disease has been registered in the Ural, Far Eastern and North Caucasus regions. The highest incidence was noted in the Kamchatka and Magadan regions, the Chukotka and Koryak autonomous districts, the Republic of Sakha (Yakutia), and the Orenburg region.
Routes of infection
The source of human infection is animals: dogs, foxes, wolves, jackals.
Human infection can occur
- when cutting the skins of wild animals,
- contact with infected dogs,
- eating unwashed berries, herbs and vegetables from gardens frequented by infected animals,
- when drinking raw water from contaminated sources.
Echinococcosis often occurs in hunters when they feed raw wild animal entrails to their dogs.
Cattle and small cattle can be mechanical carriers of eggs that fall onto animal fur from contaminated grass.
Health effects of Echinococcus
Oncospheres settled in human organs turn after 5 months into larvae (echinococcal cysts) with a diameter of 5-20 mm.
Several organs can be affected at the same time. The size of the larvae can vary from 1-2 cm to giant ones, containing several liters of liquid.
A growing cyst pushes away the tissue of the affected organ, causing inflammation and death. Gradually, the area of inflammation is replaced by scar tissue, and the organ becomes deformed.
A large cyst may rupture. In this case, its contents enter the abdominal region or the lungs, bronchi, bile ducts or large vessels, which often leads to severe anaphylactic shock, infection of other organs and secondary echinococcosis.
Symptoms
The first symptoms of infection are nonspecific:
- general intoxication,
- weakness,
- malaise,
- nausea,
- Possible rash with itching.
When the liver is infected, the symptoms are similar to pain due to cholecystitis
- pain in the upper right side of the abdomen,
- weight loss,
- lack of appetite,
- heartburn,
- belching,
- vomit.
Growing echinococcal blisters in the liver compress large bile ducts, causing obstructive jaundice.
Manifestations of pulmonary echinococcosis are manifested by such symptoms as
- chest pain,
- dry cough,
- hemoptysis.
Renal echinococcosis is often diagnosed only when urine formation is delayed and is accompanied by nagging pain in the lumbar region.
The main symptom of bone echonococcosis is pain and swelling in the affected area.
Intestinal echinococcosis is manifested by general intestinal symptoms and symptoms depending on the location of the echinococcal bladder:
- abdominal pain, especially at the location of the bladder,
- nausea,
- vomit,
- stool disorders.
When the bladder grows, intestinal obstruction may develop.
Diagnostics
Diagnosis of echinococcosis is based on data from X-ray, ultrasound and immunological studies.
The best method for identifying hydatid cysts is ultrasound . They look like rounded formations with clear contours.
CT and MRI make it possible to determine the nature of the lesion, its size, complications, lesions and the condition of the affected organ.
Laparoscopy has limited value, since the method does not provide certain information, and the risk of complications is high.
Serological methods are highly informative, allowing the detection of specific antibodies to echinococcus.
Treatment
The main method of treatment for echinococcosis is surgical - surgical removal of the cyst with drainage of its cavity, or less often, removal of part of the affected organ.
Treatment with drugs is possible for the following indications:
- single cysts no larger than 3 cm in diameter,
- multiple cysts no larger than 1 cm in diameter,
- rupture of an echinococcal cyst,
- opening of an echinococcal cyst of the lung into the lumen of the bronchus and its emptying,
- inoperability.
For conservative treatment, albendazole and mebendazole .
The effectiveness of treatment with the drug is 70-80%.
Further treatment is aimed at correcting metabolic and immune disorders.
Prevention
After treatment, observation by a doctor is necessary for 5 years.
After surgery, you must undergo examination 1-2 times a year:
- general analysis of urine and blood,
- biochemical blood test: ALT, AST, bilirubin, proteinogram, antibody level,
- Ultrasound of the abdominal cavity.
According to indications, examination by the following specialists is necessary:
- neurologist,
- pulmanologist,
- gastroenterologist
To prevent infection you must:
- observe the rules of personal hygiene when caring for animals,
- wash berries, fruits, vegetables, etc.,
- carry out deworming of dogs,
- destroy the internal organs of infected animals.
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