A. lumbricoides life cycle

Ascaris lumbricoides, a type of intestinal parasite, begins its life cycle when eggs are excreted in human stool. These eggs mature in the soil over a few weeks, becoming infectious. If someone ingests contaminated food or water containing these eggs, they hatch into larvae in the small intestine. The larvae then penetrate the intestinal wall, travel through the bloodstream to the lungs, mature further, and eventually move up the bronchial tubes to the throat, where they are swallowed again. Back in the intestine, they develop into adult worms, reproduce, and release eggs, continuing the cycle.