What is pinworm infection?
Pinworm infection is caused by the helminth (Enterobius vermicularis), a small, white parasitic worm. The pinworm is about the length of a staple (ranges from 2 to 13 mm [0.08 to 0.5 inches]) and lives for the most part in the rectum of humans. While an infected person is asleep, female pinworms exit the intestines through the anus and deposit eggs on the skin around the anus. Within a few hours of being deposited on the skin around the anus, pinworm eggs become infectious (capable of infecting another person). Pinworm eggs can survive up to three weeks on clothing, bedding, or other objects if the environment is sufficiently moist.
What is the pinworm test?
If pinworms are suspected, transparent adhesive tape or a pinworm paddle (supplied by your healthcare provider) is applied to the anal region. The tape can pick up both eggs and occasionally the adult worms. Most clinicians suggest the test be done as soon as the person awakens and before any bowel movement or cleansing (bath, shower) as these actions tend to remove the eggs and parasites from the anal/rectal area.
The pinworm eggs or a few adult worms adhere to the sticky tape or paddle and are identified by examination under an ordinary microscope by a qualified laboratory technician.
In some individuals, it is possible to see the adult worms without a microscope, but the transparent eggs are small and can only be seen with a microscope.
When should the pinworm test be done?
The test should be done as soon as you wake up in the morning (because bathing or having a bowel movement may remove eggs). The exam may require several samples for a positive diagnosis. Researchers suggest that repeating the test at about three different intervals yields about a 90% detection rate.