Which organism is associated with ascariasis?

Ascariasis is a parasitic infection caused by the roundworm Ascaris lumbricoides. This organism primarily resides in the small intestine of its host. Adult worms can reach significant lengths and are known to ingest nutrients from the host's diet, leading to various health issues including malnutrition and intestinal blockages if the infection is severe.

Understanding the life cycle of Ascaris lumbricoides helps clarify its location within the body. After ingestion of eggs found in contaminated food or soil, the larvae hatch in the intestines. They migrate through the bloodstream to the lungs, where they can be coughed up, swallowed, and returned to the intestines to mature into adult worms. However, the definitive location where they reside and reproduce is the small intestine, making this the correct association for ascariasis.