Comments - This is the most common helminth infection in the United States. Clinical Correlation Main symptom is pruritus ani due to female laying eggs in perianal area at night. Urethritis, vaginitis, salpingitis and pelvic peritonitis may occur doe to migration of adult worms from the perineum.
Transmission is hand to mouth.
Re-infection and autoinfection is common and maintain infection since female worms die after depositing eggs on the perianal skin. Eggs remain infective indoors for 2-3 weeks. Incubation period is 1-2 months or longer after ingestion. Eggs hatch in the duodenum, larvae migrate to the cecum, mate and gravitate to the perianal skin where females deposit eggs. Diagnosis is accomplished by observing biscuit shaped eggs.