Hydatid disease


The hydatid disease is a potentially life-threatening infection with the fox or dog tapeworm. The symptoms depend on the affected organ. In most cases, the liver is affected. Find out here about symptoms, diagnosis and treatment of an echinococcosis.

ICD codes for this disease: ICD codes are internationally valid medical diagnosis codes. They are found e.g. in medical reports or on incapacity certificates. B67ArtikelübersichtEchinokokkose

  • description
  • symptoms
  • Causes and risk factors
  • Examinations and diagnosis
  • treatment
  • Disease course and prognosis

Echinococcosis: description

Echinococcosis is a worm disease that is usually triggered by the parasitic dog or fox tapeworm. Two very different clinical pictures are distinguished: on the one hand, the alveolar echinococcosis caused by the small fox tapeworm (Echinococcus multilocularis) and, on the other hand, the cystic echinococcosis caused by the small dog tapeworm (Echinococcus granulosus).

While the dog tapeworm is a worldwide problem, the fox tapeworm occurs only in certain regions, including Central Europe and especially southern Germany. In 2014 there were 66 cases of cystic echinococcosis in Germany. 16 people were affected by alveolar echinococcosis, reports the Robert Koch Institute. In these regions, up to 75 percent of foxes are infected with the small fox tapeworm. The average age of onset of fox tapeworm infection is between 50 and 60 years. Children and adolescents are rarely affected. The dog tapeworm triggered echinococcosis affects all age groups.

What are tapeworms?

Tapeworms (Cestodes) are parasites. They consist of a head with mammals and barbs, a neck and a long, band-shaped body. This is divided into individual, similarly structured sections. Tapeworms are hermaphrodites that have no intestines and therefore absorb the food through the skin.

A tapeworm goes through different stages in the course of its development. Depending on the stage, he refers to another host. Carnivorous animals, especially fox and dog, and more rarely cats, pick up the larvae by eating the meat of an infected animal. In the intestine of these end hosts, the larvae develop into tapeworms laying eggs. This happens by always repelling the last limb of his body, which is filled with eggs. A dog tapeworm can lay around 1,500 per section of the body - a fox tapeworm around 200. The eggs are excreted in the feces and in turn by an intermediate host (for example, mice), where they form a kind of cyst or encapsulation, especially in the liver. Even humans can inadvertently serve as intermediate hosts.

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Echinococcosis: symptoms

For many years, an echinococcosis can remain completely unremarkable. During this time the cysts get bigger and bigger and can affect the organs in which they are located. This can reveal an echinococcosis: The echinococcosis displaces or infiltrates organs and leads there to pressure and compression of nerves, vessels or organs. The symptomatology depends strongly on the affected organ. Also an additional infection with bacteria is possible. It can also lead to nonspecific symptoms such as malaise, weight loss and allergic reactions.


In about 70 percent of cases, the liver is affected by an echinococcosis. The consequences are pressure and pain in the right upper abdomen. If the worm infestation obstructs the bile flow, skin and eyes may turn yellow (icterus). This may result in inflammation of the biliary tract (cholangitis), cirrhosis of the liver, and blockage of the portal vein that directs blood into the liver (portal hypertension).


About 20 percent of dog tapeworm infections are in the lungs. In fox tapeworm infections, lung involvement is rare. The main symptom is cough, sometimes bloodier. In addition, sufferers suffer from pain and respiratory disorders.

No organ is protected from an echinococcosis!

Especially in cystic echinococcosis, cysts can occasionally be found in the brain, spleen, heart, bones and other organs. Infestation can be via the bloodstream, the lymph, but also by direct sowing in the abdominal or thoracic cavity.

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Echinococcosis: causes and risk factors

For the fox and the dog tapeworm man is a false intermediate host. The larvae nest in various organs, but rarely develop into worms. For those whose immune system is affected by disease or therapy, the disease can be more severe.

The infection with the tapeworms takes place in the vast majority of cases by the food containing eggs from the feces of infected animals. In particular, the consumption of unwashed berries, fallen fruits or fruits of low shrubs carries a high risk of infection. But it is also possible to become infected by eating raw meat.

After ingestion, the eggs usually enter the liver through the intestinal blood vessels. From there they can reach other organs in the course. In the organs, the eggs develop into larvae, which become tumor-like, and perhaps only become noticeable after years.

No transmission from person to person

The disease is not transmitted from person to person. Patients usually do not risk infection. Also, the operated material is considered non-infectious.

Dog and fox tapeworm have very different growth patterns, which are crucial for the different disease patterns of the two worm diseases:

Of the Dog tapeworm makes cysts in the organs. Cysts are liquid-filled cavities. Cysts caused by the dog tapeworm displace the surrounding tissue and are usually single. The cysts cause the body's own tissue to form a wall around them.

The alveolar echinococcosis by the Tapeworm leads to infiltration of the organs - much like a cancer. They are also spongy and built together by chambering chamber.

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Echinococcosis: examinations and diagnosis

First, you should turn to suspected a worm infestation to an infectious. However, the care and treatment of echinococcosis should be done in a specialized center for worm infections. Since one-third of all cases are incidental findings, most patients will be referred to a specialist immediately after the findings are collected. The doctor will, among other things, ask these questions:

  • Have you ever been diagnosed with a worm or other parasitic disease?
  • Inexplicable abnormalities have been found during previous investigations?
  • Do you feel pain or pressure in the right upper abdomen?
  • Do you suffer from (inexplicable) diseases of the lungs (eg cough)?
  • Are you aware of previous illnesses?
  • Which medications do you take?

The most important diagnostic tool in an echinococcosis is imaging. To locate the affected organs, the ultrasound, MRI and CT technique can be used. Due to the frequent calcification of the cysts, they are clearly visible. Thus, foci of cystic echinococcosis are smoothly bordered and calcified especially on the margin. Their daughter cysts typically have a double contour in the wall and a honeycomb structure. Usually, an ultrasound examination is performed first. Already with the help of this examination abnormalities in the liver can be detected. Imaging is so important because a cyst may never be punctured if it is suspected of having an echinococcosis, as this may spread eggs throughout the body.

Further investigations

To clarify an echinococcosis also includes the blood test. In the standard blood test, in about ten percent of cases, the rise of a subset of white blood cells (eosinophils) can be noticed. It is believed that eosinophils have a role in worm defense. The doctor should send the collected blood to a specialized echinococcosis laboratory. While shipping may take a little more time compared to local lab testing, specialized laboratories can provide better quality results. There, worm-specific antibodies and antigens can be detected and investigated. A negative blood test does not rule out an echinococcosis.

However, no definitive diagnosis can be made both by image and blood tests. Nevertheless, a report to the Robert Koch Institute is always necessary if there are clear findings. For this reason, the final diagnosis should be continued with a reasonable suspicion at an experienced center, such as at the University Hospital Würzburg, the consultation laboratory of the Robert Koch Institute.

The definitive diagnosis can be made by a pathological examination of material taken after surgery. With the aid of the PNM classification, the fox tapeworm infestation can be estimated. This classification takes into account the involvement of the liver (P), the neighboring organs (N) and existing metastases (M).

For therapy monitoring, a special imaging examination, the FDG-PET, can be used. Using this technique, the activity of the worm hydatids can be tested.

More common than an echinococcosis are liver tumors, which can look very similar in imaging. A number of other alternative diagnoses are conceivable. These include different benign and malignant tumors, different types of cysts, abscesses or even tuberculosis.