What is it about ?
Ascariasis is a cream-colored earthworm infection, Ascaris lumbricoides, 15 to 40 centimeters long and 3 to 6 millimeters wide in adulthood. Contamination begins after ingesting the eggs of the worm that have ended up on the ground or in irrigation water via the stool. Eggs only become contagious if they have been on the ground for several weeks, so infection through direct contact is unlikely. The larvae are found in the digestive tract, and eventually enter the blood. Via the bloodstream, they reach the lungs, and from there migrate to the pharynx, where they are again swallowed and enter the intestines, where they become adult worms.
Apart from human earthworms, there are also earthworms which use the animal as a host. The most common are roundworms in dogs and cats (Toxocara canis and T. cati). These worms cause toxocariasis.
What is its frequency?
Ascaridosis is a disease found all over the world. In the past it was common in Belgium, but it has become much rarer today. In developing countries, ascariasis is still widespread, with an estimated 2 billion cases. Fatal cases (around 75,000 each year) are observed only in these countries.
On the other hand, contamination by roundworm in dogs and cats is much more frequent in Belgium.
How to recognize it?
Usually the person does not have symptoms. If there is, they are very light. The most common symptoms are nausea and stomach aches, ranging from mild intensity to sensations of colic. During the migratory phase of the larvae, the person may develop a cough, fever and urticaria.
Adult worms can be dangerous if they migrate to the bile ducts as they can block the bile ducts, or if they enter the intestinal wall as this can cause, for example, peritonitis. If the worms are numerous, they can block the intestine (intestinal obstruction). These complications, potentially fatal without treatment, are rare.
Worms can also lead to vitamin A deficiency and undernutrition, due to the loss of protein and energy nutrients (nutrients necessary for the body to function properly).
How is the diagnosis made?
The doctor can make the diagnosis after a microscopic examination of the stool where he identifies eggs or worms. During the migratory phase, the doctor may observe certain abnormalities in the blood.
What can you do ?
Ascariasis should always be treated. Try to avoid exposing yourself to illness by using clean sanitary facilities and heating your food before eating it.
What can your doctor do?
Your doctor will prescribe medication. His choice will be mebendazole in adults and children over 2 years, at a rate of 100 mg twice a day for 3 days.
The effectiveness of the treatment is checked after 3 weeks using a stool sample.
Want to know more?
- Healthy travel – IMT – Institute of Tropical Medicine
- Mebendazole – CBIP – Belgian Center for Pharmacotherapeutic Information
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