Intestinal nematode; roundworm
Endemic in tropical/subtropical areas such as Africa, Southeast Asia, Central/South America
Present in contaminated soil → larvae penetrate skin of hosts walking barefoot → enter venous circulation, migrate to lungs, then are expectorated to pharynx and swallowed → larvae develop into females that lay eggs asexually into GI tract, which hatch into larvae and are excreted into stool
Larvae either become sexually reproducing males/females or filariform larvae that can reinfect host
Autoinfection: Unique to<unk> ; GI larvae can migrate from GI tract to venous system, then to lungs and proceed with life cycle
Can lead to dramatic increase in worm burden and hyperinfection in immunocompromised
Can lead to dramatic increase in worm burden and hyperinfection in immunocompromised
Corticosteroid use, immunosuppression
Transplantation
Hematologic neoplasm (e.g. leukemia)
Human T-lymphotropic virus-1 infection (HTLV-1)
Malnutrition
Diabetes
Chronic renal failure
Chronic alcohol use
Chronic infection in immunosuppressed can lead to fulminant dissemination with case fatality rate as high as 70%; strong index of suspicion is needed in such cases
Strongyloides stercoralis
Inflammatory bowel disease
Ascaris lumbricoides
Schistosomiasis
Trichuris trichiura
Filariasis
Taenia saginata
Hookworm