Ascariasis is an infection with a nematode (worm) parasite known as ascaris lumbricoides.

This round worm can reach up to 40 cm (15.7 inches) in length. Their eggs hatch in the stomach and travel to the heart and lungs. This causes a type of pneumonia. They travel to the throat where they are swallowed and enter the stomach again and develop into adult worms. Each worm lays 240,000 eggs per day. These eggs leave the body with bowel movements. The cycle begins again when contaminated food or water is eaten.

Digestive Tract and Lungs
Digestion tract and Lungs 3D
Copyright © Nucleus Medical Media, Inc.

Ascariasis is caused by swallowing food or water that is contaminated by feces containing eggs.