What Are Threadworms?

Infection by threadworms is extremely common and can occur in people of all social groups, even in the cleanest of homes. Also known as pinworm, seat worm and enterobiasis, it is one of the oldest known of human infections, threadworm eggs having been found in fossils 100,000 years old.

The worm lives in the intestines and during sleep the female crawls into the anus and lays up to 10,000 eggs which cause severe itching. Patients scratch the anus; the eggs get under the fingernails and eventually into the mouth, then down into the intestines where they hatch and the cycle begins all over again. Eggs may also contaminate nightclothes and bed linen, where the infection can lie for two or three weeks. The worms, which are like little strands of white cotton less than 13 mm. in length, can be seen wriggling in the faeces.