Humans become infected by ingestion of infected embryonated eggs which reach the mouth by inhalation, hand to mouth transport, or in contaminated food or drink. Infections many times involve families living under crowded conditions. Sometimes the entire family may be infected. Male and female adult worms live in the colon and mate. Scratching of the anal area may lead to dermatitis and secondary bacterial infections.
Scratching also dislodges the eggs providing a potential source of infection to sibling and parents.
The sticky part of the clear transparent cellulose tape is applied to the perianal region usually in the morning when the patient first awakes. Eggs stick to the transparent tape. The tape is placed sticky side down on a glass microscope slide and examined microscopically for the very characteristic eggs which are 55 um x 25 um wide, ovoid with a thick clear shell and flattened on one side . Internally there is a developing larva. Sometimes the adult female worm may even be present in the scotch tape preparation.