JOURNAL OF THE LOUISIANA STATE MEDICAL SOCIETY
Strongyloides stercoralis ; Strongyloides hyperinfection syndrome, hyperinfection; Strongyloides autoinfection, autoinfection; disseminated strongyloidiasis; helminth, nematode, parasitic diseases; immunosuppression; HTLV-1; prisoners of war, POWs, infectious diseases. Articles selected for review included case reports and series, observational studies, descriptive epidemiological studies, and parasitological investigations. Since this investigation was a review of prior published scientific articles, Institutional Review Board approval was not required.
and is initially infected by third stage filariform larvae in feces- contaminated soil that penetrate intact skin on contact and migrate to the intestinal mucosa, most commonly in the duodenum, where they molt twice and become adult females. Initially, parasitologists believed that the infective filariform larvae migrated to the lungs first and caused a transient Loeffler’s syndrome during which they were coughed up and swallowed for transit to the duodenum. New evidence, however, has confirmed that filariform larvae can migrate directly to the small intestine via connective tissues. The adult females in the intestinal mucosa produce eggs by parthenogenesis which become rhabditiform larvae that are either excreted in feces or become infective filariform larvae and penetrate the intestinal mucosa (internal autoinfection) or the perianal skin (external autoinfection). Autoinfections result in a chronic and relative asymptomatic infection that persists over a lifetime unless treated.
RESULTS
The Life Cycle of Strongyloides stercoralis
The life cycle of Strongyloides stercoralis is much more complex than that of other nematodes because of its parasitic and free- living stages and its unique ability to cause internal and external autoinfections and hyperinfections in man (Figure 1). Man is the reservoir host for the asexual parasitic stage of strongyloidiasis
Figure 1: The life cycle of Strongyloides stercoralis. Source: United States Centers for Disease Control and Prevention (CDC), DPDx Image Library. No copyright permission required. Available at https://www.cdc.gov/dpdx/strongyloidiasis/index.html
J La State Med Soc VOL 170 JANUARY/FEBRUARY 2018 19
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