Strongyloidiasis as a Cause of Chronic Diarrhea, Identified Using Next-Generation Strongyloides stercoralis-Specific Immunoassays

Abstract

A 63-year-old-male Vietnam War veteran noted a 6-month history of watery diarrhea. A colonoscopy 6 months prior to presentation was significant for colonic mucosa with inflammation, sheets of eosinophils, and an acellular structure, which was suspicious for a parasite. Initial laboratory testing on presentation revealed an elevated eosinophil count, prompting an investigation for a parasitic infection. Three stool microscopy examinations were negative for parasite ova and larvae, but the patient had a positive Strongyloides immunoglobulin-G antibody on an enzyme-linked immunosorbent assay (ELISA). Confirmation of S. stercoralis infection was achieved using a Strongyloides-specific luciferase immunoprecipitation systems (LIPS) assay. Accurate diagnosis of Strongyloides infection is particularly crucial for patients who are currently immunocompromised or will be immunosuppressed with medications, as immunosuppression can lead to accelerated autoinfection and systemic dissemination, which, if untreated, carries a fatality rate of nearly 100 %.