Epidemiology & Risk Factors

Ascariasis caused by Ascaris lumbricoides is one of the most common intestinal worm infections. It is found where access to personal hygiene and proper sanitation practices are not available, and in places where human feces is used as fertilizer.

Ascariasis caused by Ascaris suum is found where there are pigs. People who raise pigs or use raw pig manure as fertilizer may be at risk. Contact with pigs should be considered when someone is diagnosed with ascariasis.

Geographic Distribution

Ascaris lumbricoides infections happen all over the world. The eggs from the parasite are passed in human feces and can contaminate the soil. The eggs survive best in warm, humid areas and must grow in the soil before they can infect others. Most cases occur in tropical and subtropical areas of Asia, sub-Saharan Africa, and the Americas

Ascaris suum is found wherever pigs are found.

Page last reviewed: November 23, 2020