Yes, these little creatures are very contagious. Although pinworms are not as common in the U.S. as in other parts of the world, they are still prevalent among young children and their parents.

Pinworms are spread via the "fecal-oral" route, meaning they originate from the feces and are ingested through the mouth. Most commonly, worm eggs are carried on fingers and hands from one host to the next. But they may also be spread through shared clothing, toys, bedding, baths, and even toilet seats, although this is much less common. The eggs can live and remain infective for as long as three weeks in an indoor environment. After they are ingested, the eggs hatch in the stomach, travel through the small bowel, and mature into adult worms in the large intestine. When they are fully grown, pinworms are about 1 centimeter in length and white in color.

At night the pregnant females migrate to the anal area, where they lay their eggs and then die. It is these eggs that are responsible for the symptoms of pinworm infestation -- itchiness and irritation around the anus, which can lead to sleeplessness. Less often they can migrate to the vaginal area and cause similar symptoms in the female genital tract. The itchiness leads to scratching and to the depositing of eggs beneath the child's fingernails. This, in turn, leads to spread of the worms unless kids thoroughly and frequently wash their hands.

The incubation period -- from the time of ingestion to the moment when the first female lays her eggs -- is one to two months or longer. Because of the long incubation period, people can become infected and not know it. Often, friends and family members in close contact with the child may also need treatment, even if they don't yet have symptoms.

Diagnosis is relatively simple. At night, after the child has been asleep for about an hour, parents should turn him or her over and, using a flashlight, look carefully at the rectal area. Live, threadlike worms may be seen wiggling out of the anus to lay their eggs. Collect the worms and/or eggs by pressing cellophane tape against the anal skin, and, the next day, bring the specimen to the pediatrician for closer inspection. If you don't notice anything at night, check for eggs in the morning. (Although pediatricians can perform this test in their office, the results are more fruitful late at night or first thing in the morning, which is why doctors recommend that parents gather the evidence.) For best results, three separate specimens should be obtained from the child before he or she bathes in the morning.

Although irritating, pinworms rarely cause serious problems. Luckily, pinworm infections are easily treated with either mebendazole or pyrantel pamoate given in a single oral dose and often repeated two weeks later.

Because pinworms are spread from the rectum to the mouth, frequent and scrupulous hand-washing -- 10 to 20 seconds of scrubbing with warm water and soap -- will help prevent the spread of pinworms and most other communicable diseases, including colds and viruses. Finally, parents must launder all the child's undergarments, bed linens, towels, and nightclothes, and bathroom facilities at school and at daycare should be disinfected.
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