What are worms?

Worms are parasites. They settle in humans mainly in the digestive tract and can cause diseases under certain circumstances. Worm diseases can occur worldwide, but are rather rare due to the good hygienic conditions in our latitudes. The worm diseases that occur in Germany are therefore rather harmless and can be cured quickly with the appropriate therapy. Most of these diseases are caused by pinworms, for example. Children in particular are affected more often than average by mostly harmless worm diseases. However, many of the worm diseases can be treated well with the appropriate worming medication.

What is a worm disease?

Worm diseases are also called helminthoses. They are caused by worm infestations and often affect the gastrointestinal tract and/or other organs such as the liver, lungs or brain. The most common worms that can pass on to humans include tapeworms (cestodes), threadworms (nematodes) and sucking worms (trematodes).

What are the symptoms of worm infections?

The following rather non-specific symptoms may indicate worm disease:

• Sleep problems,
• Difficulty concentrating,
• Abdominal pain, which can be accompanied by bloating and pressure in the upper abdomen,
• Nausea,
• Loss of appetite,
• Skin changes and/or itching in the anal area,
• Excretion of worms or worm parts in the stool,
• Weight loss,
• Paleness and weakness, which can be caused by anaemia,
• Jaundice, shortness of breath and irritable cough may indicate dog or fox tapeworm,
• Fever, headache and abdominal pain, as well as blood in the stool and/or urine after travelling to Asia and/or Africa can indicate sucking worms (schistosomes).

How can you get infected with worms?

Especially in the case of the worm species that are particularly common in Germany, infection usually occurs through the mouth. For example, worm eggs can be found on contaminated vegetables, fallen fruit, in the sand or in the soil. Since small children in particular often put dirty hands, sand or objects in their mouths, they are affected by worms more often than average. However, worm infections can also be transmitted by eating raw or half-cooked meat that is infected with worm larvae. This is the case with tapeworms, for example. Once the worm eggs or larvae have been ingested by mouth, they can develop into adult worms in the body. Depending on the type of worm, the eggs or parts of the worm can be excreted in the stool.

What types of worms are distinguished?

The following types of worms are particularly common in our latitudes:

• Threadworms (nematodes): These include the so-called pinworms (oxyurans, Enterobius vermicularis). They are ingested via contaminated food, toys or laundry. Children in kindergarten or primary school are particularly often infected with threadworms. They can grow up to 12 mm long and settle in the lower small intestine, the large intestine or the appendix.
• Roundworms (Ascaris lumbricoides): They are often ingested through contaminated vegetables and settle in the small intestine of humans, lay their larvae here, which in turn pass through the intestinal wall into the blood and through the bloodstream into the liver and lungs. During this migration, people may suffer from mild fever, cough or other flu-like symptoms. The roundworms can grow up to 40 cm long and form nodules in the intestine, thus closing off the intestine.
• Trichinae (Trichinella spiralis): are particularly common in domestic and wild pigs and can be transmitted to humans by eating raw pork. Trichinae, if they settle in the intestine, cause watery diarrhoea, nausea, vomiting and mild fever. If the larvae of the trichinae infect the muscles, the result can be muscle pain or water retention. If the trichinae reach the heart, they can cause myocarditis. In the brain, they cause neurological symptoms.

How is worm disease diagnosed?

If a worm infestation is suspected, the doctor will usually carry out a microscopic stool examination. This reveals the worm eggs, which proves the infection. If the worms are tapeworm members of the bovine and porcine tapeworm, for example, they are already visible to the naked eye in the stool. The eggs of roundworms can be secured by applying a piece of tesa film to the intestinal outlet. This is because the eggs sticking to the tesa can be made visible under the microscope.

If, on the other hand, there is a suspicion of acute schistosomiasis (sucking worms) in travellers returning home, the eggs of the sucking worms can be detected in the stool about 5 to 12 weeks after the suspected infection. Alternatively, a test for antibodies in the blood can be carried out.

How can worm infections be treated?

The worm diseases that occur in our latitudes can usually be treated well by the doctor with so-called anthelmintics. The medication kills the worms and they can be excreted. Depending on the type of worm, different medicines can be used, such as pyrantel, albendazole or mebendazole. Often, a single dose of the medication is enough. In more severe cases of worm infestation, it may be necessary to take the medication for three days or over a longer period of time. Sometimes it may be advisable to repeat the treatment after about two weeks to prevent a new worm infestation.

To support the appropriate treatment, hygiene should be observed in any case. This is the only way to prevent a new infection, but also to protect the environment accordingly. The following hygiene measures should be observed:

• thorough and frequent washing of hands with soap: this applies in particular after each visit to the toilet, before eating and, in the case of children, after playing outdoors.
• Cut fingernails short and do not bite your nails
• careful intimate hygiene
• change underwear every day
• Changing bed linen after worm treatment
• Washing bed linen and underwear at at least 60° Celsius

What is the prognosis after a worm infection?

If the worm infestation is mild, the infection should clear up quickly after the appropriate worming medication. If, on the other hand, organs have been affected, the chances of recovery depend on the extent of the worm infestation. If the bladder has been affected, the risk of bladder cancer developing at a later stage increases.