Ascariasis (as-kuh-RIE-uh-sis) is a type of roundworm infection. These worms are parasites that use your body as a host to mature from larvae or eggs to adult worms. Adult worms, which reproduce, can be more than a foot (30 centimeters) long.
One of the most common worm infections in people worldwide, ascariasis is uncommon in the United States. Most infected people have mild cases with no symptoms. But heavy infestation can lead to serious symptoms and complications.
Ascariasis occurs most often in children in tropical and subtropical regions of the world — especially in areas with poor sanitation and hygiene.