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Ascaris lumbricoides

Ascaris lumbricoides

An adult female Ascaris worm.
Scientific classification
Kingdom: Animalia
Phylum: Nematoda
Class: Secernentea
Order: Ascaridida
Family: Ascarididae
Genus: Ascaris
Species: A. lumbricoides
Binomial name
Ascaris lumbricoides
Linnaeus, 1758

Ascaris lumbricoides is the member of the Ascaris family responsible for the disease Ascariasis.

Ascaris lumbricoides, or "roundworm", infections in humans occurs when an ingested infective egg releases a larval worm that penetrates the wall of the duodenum and enters the bloodstream. From here, it is carried to the liver and heart, and enters pulmonary circulation to break free in the alveoli, where it grows and molts. In 3 weeks, the larvae pass from the respiratory system to be coughed up, swallowed, and thus returned to the small intestine, where they mature to adult male and female worms. Fertilization can now occur and the female produces as many as 200,000 eggs per day for a year. These fertilized eggs become infectious after 2 weeks in soil; they can persist in soil for 3 years or more.[1]

Infections with these parasites are more common where sanitation is poor and human feces are used as fertilizer. Prevention of this infection centers around education, not using human feces as fertilizer, and cleanliness, especially among those who handle food. More than 1 billion people are affected by this infection.[1]


  1. ^ a b Murray, Patrick R.; Rosenthal, Ken S.; Pfaller, Michael A. Medical Microbiology, Fifth Edition. United States: Elsevier Mosby, 2005
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Ascaris_lumbricoides". A list of authors is available in Wikipedia.
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