Post-Ivermectin Strongyloides Follow-Up — SCE Infectious Diseases MCQ

Correct answer: C — Repeat Strongyloides serology at 6 months — seroconversion to negative confirms cure; however, serology remains positive for months after successful treatment so a negative stool (if obtainable) at 2 weeks is more immediately useful

Strongyloides infection must be cleared and followed up carefully before high-dose corticosteroids because immunosuppression can precipitate life-threatening hyperinfection. After ivermectin, the appropriate test-of-cure strategy is repeat Strongyloides serology at about 6 months: serology falls slowly and may remain positive for months, so 1-week serology is not useful. Seroreversion to negative confirms cure, while a substantial fall supports response; if still positive, repeat at 12 months and consider specialist advice. For a more immediate pre-immunosuppression check, stool testing at about 2–4 weeks after treatment is useful if larvae were previously detected or a specimen can be obtained, but stool microscopy is insensitive and a single negative sample cannot fully exclude infection. Eosinophil count alone is inadequate and no follow-up is unsafe.

Reference: Royal Children’s Hospital Melbourne Immigrant Health Service. Strongyloidiasis clinical guideline, updated June 2020/current webpage: https://www.rch.org.au/immigranthealth/clinical/Strongyloidiasis/; compatible with UKHSA Helminth infections: migrant health guide, updated March 2025: https://www.gov.uk/guidance/helminth-infections-migrant-health-guide