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Pinworms are the most common intestinal worm infection in the U.S. Most often they are found in preschool and school-aged children and their parents. These small, threadlike worms (0.25– 0.5 inches long) are found in the human intestines and crawl out of the rectum at night to lay eggs.

What causes Pinworm?

Enterobius Vermicularis, a parasite

How is Pinworm spread?

Pinworm eggs are taken into the mouth when a person fails to wash hands well after scratching the rectal area, using the toilet, or handling contaminated pajamas, underwear or bedding. Food or other items can be contaminated the same way

What are the symptoms of Pinworm?

Rectal (bottom) itching, especially at night; irritability; disturbed sleep; may have no symptoms.

How long is it contagious?

As long as eggs are present. Eggs can remain infectious outside the body for as long as two to three weeks.

How can I prevent infection?

  1. Frequent, careful hand washing by child care staff, children and household members.
    • When a child wakes up, you may see the worms around the rectum or in the stool. If you suspect pinworms, contact your health care provider. He/she may advise examining the whole family.
  2. Avoid scratching or touching bare rectal area or biting nails. It is important to keep fingernails short, groomed and clean.

What should I do if there is an infection?

  1. Bathe every morning (shower preferred), using a clean washcloth and towel, followed by a clean change of underclothing.
  2. Change bedding and clothing daily and wash in hot water. Do not shake bedding to prevent spreading eggs through the air.
  3. Clean and vacuum house daily.


For more information, please call the Northern Kentucky Health Department at 859.363.2070.

Sources: Northern Kentucky Health Department, Centers for Disease Control and Prevention

Revised July 2015