A 6-year-old girl presents with intense perianal itching, especially at night. Physical examination reveals perianal excoriation. An adhesive tape test is positive for worms. Which of the following is the most likely parasite in this patient?

E. vermicularis ("pinworm") is an intestinal nematode that is encountered worldwide but is more common in temperate zones. Individuals can be infected at any age, but parasitism is more common in children. Most people complain of pruritus caused by migrating worms. Ancylostoma duodenale and Necatoamericanus (choices A and D) are hookworms associated with intestinal bleeding and iron-deficiency anemia.Diagnosis: Enterobiasis