Groups at risk for intestinal helminth infestation include international students and travelers, migrant laborers, refugees, children of foreign adoptions and the homeless. Symptoms are often minimal or vague, yet many such infections carry significant long-term morbidity. Enterobius vermicularis, the common pinworm, is usually manifested in children as anal itching and is best diagnosed by using the cellophane-tape test to recover eggs from the perianal skin. Treatment with mebendazole is indicated for the entire family. Trichuris, or whipworm, infection may be found with Ascaris infection, but whipworms are longer-lived and more likely to produce symptoms that mimic those of inflammatory bowel disease. Treatment for these parasites is mebendazole. Other significant helminthic infections, which are currently more common in immigrant populations, include hookworms (Necator americanus, Ancylostoma duodenale), threadworms (Strongyloides) and various tapeworms (Taenia, Diphyllobothrium and Hymenolepis species).