Lately, when I've gone to the bathroom, I've found little white worms. What are they? What should I do about them?

Rachel

Many species of parasitic worms can infect humans. Most are acquired in underdeveloped countries, areas with poor sanitation or in tropical regions.

But if you live in a developed country and haven't recently traveled to the tropics, your "little white worms" are most likely pinworms, known to scientists as Enterobius. These 1cm-long parasitic worms are not a serious health threat, but they can cause itching in the anal area. School-age children are usually the first to be infected. Scratching causes the worm's eggs to lodge under fingernails. The eggs are then passed along to other family members by direct contact or through contaminated food, dishes or bedding.

You should see a doctor to make sure those worms really are pinworms and to receive the proper therapy. To diagnose pinworms, a doctor may press cellophane tape against the anus to collect any eggs. The doctor then examines the tape under a microscope.

The treatment for pinworms is one dose of an antiparasitic drug (typically, mebendazole or albendazole). All household members and sexual partners should be treated at the same time. Washing all bedding and clothes is recommended, as the worms and eggs are eliminated by standard machine-wash cycles. Because the eggs can remain viable in the environment for up to two weeks, the treatment should be repeated two weeks after the first dose. Steps to prevent future infections should include maintaining good hygiene, clipping fingernails short, and washing clothes and bedding frequently.