Roundworms Life Cycle in Humans

Parasitic roundworms are commonly found in the intestines of humans. However during their life cycle, they can transport through the liver, heart and lungs. Understanding the life cycle of the roundworm can help to prevent the spread of this infection.

Eggs

• According to the Suite101.com web site, roundworm eggs are found in warm, moist soil where infected humans or animals have defacated.

Ingestion

• Roundworm eggs are ingested via unwashed, raw fruits and vegetables, dirty hands, untreated water and general inhalation.

Larvae

• Eggs pass through the stomach to the upper intestine where they hatch into larvae. The larvae burrow through the intestinal walls, and travel through the bloodstream or lymphatic system until they arrive at the lungs where they grow and develop. By the time the larvae are ready to pass from the lungs, up the airways and into the mouth, nine days have elapsed.

Maturity

• Larvae are coughed up and swallowed passing through the stomach back to the small intestine. Here, they mature, mate, lay eggs and repeat their life cycle. The process from swallowing the eggs to having mature worms in the small intestine can take between 2 and 3 months.

Warning

• In some cases roundworms do not make the complete cycle from intestine to lungs to mouth back to the intestines. They can settle in different organs such as the eyes where scar tissue may form on the retina and result in partial or total blindness.