What is the pathophysiology of stage 1 of the Strongyloides stercoralis life cycle in strongyloidiasis?

Updated: Jun 20, 2019
  • Author: Pranatharthi Haran Chandrasekar, MBBS, MD; Chief Editor: Michael Stuart Bronze, MD  more...
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Human infection is acquired by penetration of the skin or mucous membranes by infective filariform larvae, either from autoinfection or from contact with infected soil or other material contaminated with human feces (fecal-oral route) (see the image below). This is facilitated by a potent histolytic protease that is secreted by the organism. At the portal of entry, the larvae cause petechial hemorrhages, which are accompanied by intense pruritus, congestion, and edema.

First stage, life cycle of Strongyloides stercoral First stage, life cycle of Strongyloides stercoralis. Illustration by Tessa Kalman.

The larvae migrate into the pulmonary circulation via the lymphatic system and venules. Larvae migrate up the pulmonary tree, where they are swallowed, and reach the GI system. In the intestine, S stercoralis can produce an inflammatory reaction and induce a malabsorption syndrome when it attaches to the mucosal folds.

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