The eggs of the nematode are transmitted, for example with unwashed salad. Worms (parasites) use plants, animals or humans as hosts. They can live on only one host or go through one or more intermediate hosts for the final host. Worms can cause infectious diseases and are among the most common causes of infectious diseases. The most common for human nematodes are the pinworm (Enterobius vermicularis) and the roundworm (Ascaris lumbricoides). The roundworm lives mainly in Latin America, East Asia and Africa. Since the 1950s, the number of worm infections in Central Europe has declined significantly.
What can cause worm infestation
An infestation by roundworms (nematode infection) can be caused in different ways: The transmission proceeds without change of host or via one or more intermediate hosts. In the transfer without change of host, the larvae develop eggs in the open from. A few species penetrate through the skin of a host.
If the worms is transmitted via an intermediate host, the eggs develop into larvae in the intermediate host. The larvae then pass usually administered orally in the organism of the final host. Infective larvae transmitted at two intermediate hosts often insect the food on the final host.
The pinworm lives in the large intestine of humans. The female lays the eggs hatch out from the anus of the host. The larvae develop within a few hours and have a white coloration. The white eggs are also clearly visible in the feces usually. As a result of the resulting itching stored eggs are picked up and distributed by scratching with his hand. The transfer then proceeds via shared objects.
The pinworm eggs are therefore transmitted primarily within a family or shared apartment, but also in schools and kindergartens from person to person through dirt and smear infection. The self-infection occurs mainly in young children by fingers, the nails of which are contaminated with worm eggs, are placed in the mouth. The pinworm infestation (enterobiasis) is distributed worldwide. Women are affected more often than men, children and adolescents more frequently than older people.
The eggs of the roundworm are often transmitted by contaminated vegetables, such as, for example, fertilized with faeces salad. The eggs stick to the example of the salad leaves and are not removed during the wash with water. In moist soil, the eggs of the roundworm can survive for months.
From the infective eggs to the food hatch into larvae, which then burrow through the intestinal wall of its host and thus pass into the blood vessels. Via the bloodstream, they migrate through the liver to the lungs of the host. About the trachea and the onset of swallowing reflex they enter again into the small intestine. The young worms molt several times and grow in about six to eight weeks to adult. The female after mating encounters every day from about 20,000 eggs. These are excreted in the feces, the first eggs about 75 days after infection. The eggs are hard-shelled, they are highly resistant to acids and disinfectants.
What are the symptoms of worm infestation?
An infestation by pinworms often manifested by itching around the anus, which is triggered by the eggs stored there. This itching can expand when women is on the vaginal mucosa. The stool is white, threadlike worms found of about one centimeter in length.
A worm infestation is manifested by symptoms such as cough, shortness of breath, nausea, diarrhea and abdominal pain. Up to 40 centimeters long worms can be excreted with the stool. Cough and shortness of breath are related to the described migration of larvae, which migrate from the intestine of their host via blood vessels and liver to the lungs and eventually move through the trachea towards the larynx. As this movement occurs especially at night, can occur through coughing fits and disturbed swallowing difficulty sleeping.
The treatment of worm infestation
A detected worm infestation in families or nurseries requires special hygienic measures: Sufferers of anal skin and possibly the vaginal skin must undergo special treatment. In most cases mebendazole or albendazole are used with perfect results. Depending on the severity of the infestation, the treatment after 14 days must be repeated. In each case, a control examination should be carried out in consultation with the attending physician after some time to prevent a relapse.
Wearing tight-fitting underpants prevents nocturnal scratching and thus the further distribution of the eggs or bacterial infections of the skin sore. Furthermore, it is especially helpful for children who fingernails cut short to prevent dispersal of the eggs.
To kill the worm eggs have already been distributed, used textiles such as bed linen, towels and washcloths should be boiled and toys are cleaned thoroughly with hot water. Removal of the worm eggs with a vacuum cleaner only leads to a further distribution and not to the destruction of the parasite.
Before the preparation and consumption of food the hands should be well cleaned.
Are there any possible complications of worm infestation?
An accumulation of several adult roundworms can cause a bowel obstruction, which must be treated surgically. Roundworms can also migrate into the bile duct in the pancreas or in the stomach and so, for example, the flow of bile disturb (jaundice).