Ascaris is an intestinal parasite of humans. It is the most common human worm infection. The larvae and adult worms live in the small intestine and can cause intestinal disease.

Where is ascariasis found?

The roundworm is found worldwide, but it’s more frequently found in tropical and subtropical regions, including Latin America and sub-Saharan Africa. It’s also more common in areas where sanitation is poor. Environmental risk factors for ascariasis include: lack of modern hygiene and sanitation infrastructure.

What is Ascaris host?

Humans and swine are the major hosts for Ascaris; see Causal Agents for discussion on species status of Ascaris from both hosts. Natural infections with A. lumbricoides sometimes occur in monkeys and apes.