Strongyloidiasis
Epidemiology and Etiology:
- Strongyloides
stercoralis
- Endemic areas:
- southeastern US
- South America
- Sub-Saharan Africa
- Southeast Asia
- Habitat:
- Life Cycle:
- Larvae penetrate
the skin
- Travel via
circulation to the lungs
- Travel up the
trachea to be swallowed
- Female worms
reside in the mucosa of the small intestine
- Lay eggs (asexual)
- Larvae passed in
stool
- Some may invade
wall of colon and reinitiate infection (autoinfection)
- Hyperinfection may
occur in:
- Immunosuppressed
- Especially high-dose
corticosteroids
Common sites:
- Duodenum
- Ileum
- Colon
- Skin
- Lungs
Gross features:
Histologic features:
- larvae, adult
worms, and eggs in the crypts of the duodenum and ileum
- eosinophil-rich
infiltrate in the LP with mucosal edema
- in more severe
cases:
- invasion of larvae
in the colonic submucosa, lymphatics, and blood vessels
- associated
mononuclear infiltrate
- other organs:
- worms of all
stages may be found
Immunophenotype:
Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
References: