Consequences

Most worm diseases remain without consequences and can be treated well with anthelmintics and strict hygiene measures. Occasionally, however, serious diseases can occur. An example of this is echinococcosis, which is caused by a fox tapeworm infestation. Flu-like symptoms disappear with the treatment of the worm. If the worm infestation has led to a bile stasis or pancreatitis, these symptoms should be treated symptomatically in addition to the treatment of the worm in order to achieve a healing without consequences.

Worm species

In Germany, tapeworms, pinworms, trichinae and roundworms are the most common. By returning vacationers it can come in addition, again and again to the occurrence of regionally unusual worm kinds. The pinworm is a very common parasite of the human intestine.

Worldwide, about 50% of people become infected with a pinworm at least once in their lives, which leads to a rate of 500 million infections per year worldwide.The pinworm is most common in areas with a moderate climate and often infests children because of the lack of hygiene after going to the toilet. The pinworm is ingested via eggs and sucks on the intestinal wall as a larvae, where it remains until sexual maturity. After mating, the female crawls out of the human anus at night and lays her eggs in the anal folds.

These lead to itching. If the human now scratches the anus, a reinfection with the eggs can occur via hand-mouth contact. Just like the pinworms, the roundworm is also one of the threadworms.

The roundworm is characterized by the fact that during its development from egg to larvae it passes from the intestine via the liver to the lungs, where the worm infestation can lead to coughing, fever and severe mucus. If the larvae are carried to the throat during coughing and then swallowed, they return to the intestine where they mature into adult worms and can lead to colic or intestinal obstruction and malnutrition. Trichinae, which also belong to the nematodes, usually reach humans via pigs, e.g. by eating contaminated minced pork, since only boiling kills the trichinae.

Tapeworms belong to the flatworms and represent a class of over 3500 different worms. Most of them are hermaphrodites and have both male and female sexual organs. Worldwide, approximately 10 million people are infected with tapeworms every year.

The incidence in Germany is low, however, but still to be taken seriously, since an infestation by a tapeworm can be a life-threatening disease. In humans, an infection with the fox tapeworm is known as alveolar echinococcosis. The fox tapeworm is particularly common in northern countries such as Germany, Austria, Switzerland and eastern France.

The consumption of unwashed forest berries or mushrooms, but also the stroking of infested animals, whose fur is contaminated with eggs, can lead to an infection. The ingested eggs do not remain in the intestine but continue to develop in the liver. There the worms form cysts and not only displace the original tissue but also destroy it through their invasive growth.

Nevertheless, the cysts only cause symptoms after a considerable time. The fox tapeworm can spread throughout the body via the lymphatic and blood vessels. This behavior is referred to as metastasis in analogy to the spreading behavior of a tumor.

Without treatment, alveolar echinococcosis is usually fatal for humans. Echinococcosis can be diagnosed by means of sectional imaging, CT or MRI, or by ultrasound examination, which shows the cysts in the liver. In addition, however, blood tests must be performed to confirm the diagnosis.

This involves the imaging of specific antibodies. Therapeutically, an attempt is made to remove the cysts surgically. However, since the cysts can be scattered and can only be completely removed in 25% of patients, a systemic long-term therapy with an anthelmintic (albendazole or mebendazole) is usually followed.