- Ascariasis is the most prevalent nematode infection worldwide, caused by the roundworm Ascaris lumbricoides. It affects over a billion people, particularly in regions with poor sanitation.
- The infection is transmitted via ingestion of eggs in contaminated food or water.
- Ascariasis is often asymptomatic but can cause malnutrition, intestinal obstruction, and growth retardation in children.
- Its high prevalence is due to the resilience of eggs in the environment and widespread fecal contamination.
- Compared to other nematode infections, ascariasis has the largest global burden.

Reference: Davidson’s Principles and Practice of Medicine, 24th Edition, Chapter: Tropical Medicine, Page 414.