Adult female worms can grow over 12 inches in length, adult males are smaller. Ascariasis is the most common human worm infection. Infection occurs worldwide and is most common in tropical and subtropical areas where sanitation and hygiene are poor. Children are infected more often than adults. In the United States, infection is rare, but most common in rural areas of the southeast.
Most people have no symptoms.
If you are heavily infected, you may have abdominal pain. Sometimes, while the immature worms migrate through the lungs, you may cough and have difficulty breathing. If you have a very heavy worm infection, your intestines may become blocked. Ascarid eggs are found in the soil. The larvae are carried through the lungs then to the throat where they are then swallowed.