Ascaris lumbricoides
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| Ascaris lumbricoides | ||||||||||||||
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 An adult female Ascaris worm.
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| Ascaris lumbricoides Linnaeus, 1758 |
Ascaris lumbricoides is the member of the Ascaris family responsible for the disease Ascariasis.
It can reach a length of up to 35 cm.[1]
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[edit] Life cycle
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.[2]
[edit] Infections
Infections with these parasites are more common where sanitation is poor[3] 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.[2]
[edit] References
- ^ eMedicine - Ascaris Lumbricoides : Article by Aaron Laskey. Retrieved on 2008-02-03.
- ^ a b Murray, Patrick R.; Rosenthal, Ken S.; Pfaller, Michael A. Medical Microbiology, Fifth Edition. United States: Elsevier Mosby, 2005
- ^ DPDx - Ascariasis. Retrieved on 2008-02-03.
