Ascariasis is an infection of the small intestine caused by Ascaris lumbricoides which is a species of roundworm.Roundworms are a type of parasitic worm. Infections caused by roundworms are fairly common. Ascariasis is the most common roundworm infection.
Ascariasis is most common in places without modern sanitation. People get it through unsafe food and water. The infection usually causes no symptoms, but higher numbers of roundworms (heavier infestations) can lead to problems in the lungs or intestines.
You can become infected with ascariasis after accidentally ingesting the eggs of the A. lumbricoides roundworm. The eggs can be found in soil contaminated by human feces or uncooked food contaminated by soil that contains roundworm eggs. Children often become infected when they put their hands in their mouths after playing in contaminated soil, according to WHO. Ascariasis can also be passed directly from person-to-person.