Guideline sources The following summarized guidelines for the evaluation and management of strongyloidiasis are prepared by our editorial team based on guidelines from the National Institutes of Health (NIH 2021), the Center for Disease Control (CDC 2020), the Infectious Diseases Society of America (IDSA 2018), and the Barcelona Institute for Global Health (BIGH 2017). 1 2 3 4 Guidelines 1. Screening and diagnosis Screening (indications): Obtain routine screening for strongyloidiasis in immunocompetent patients at high risk of exposure to Strongyloides stercoralis infection. B Obtain routine screening for strongyloidiasis in immunosuppressed patients and candidates for immunosuppression at high or intermediate risk of exposure to Strongyloides stercoralis. B Screening (choice of test): Obtain a highly sensitive serological test for screening. Consider obtaining improved fecal techniques (Baermann or agar plate culture) if serological tests are not available. B https://web.pathway.md/diseases/recxKV1XHlJNDsQH3 1/3 6/24/23, 3:13 PM Strongyloidiasis Pathway Obtain a combination of serological and parasitological methods in immunosuppressed patients, and obtain screening before the immunosuppression if possible to avoid the risk of severe disease and because serology is less sensitive once immunosuppression has already been established. B 2. Diagnostic investigations Stool examination: obtain serial stool examinations as the gold standard for the diagnosis of Strongyloides infection. E Show 2 more Serology: Recognize that many of available serologic tests are quite sensitive, but cross-react with other filarial parasites, schistosomes, and Ascaris lumbricoides, decreasing the specificity of the tests. E Recognize that it is difficult to distinguish between active cases and historical cases since antibodies can persist for some time - a significant proportion of patients becoming antibody negative within 6 months after successful treatment. E 3. Diagnostic procedures Endoscopy and biopsy: recognize that duodenal aspirate is more sensitive than stool examination, and duodenal biopsy may reveal parasites in the gastric crypts, in the duodenal glands, or eosinophilic infiltration in the lamina propria. Recognize that larvae can frequently be seen by a simple wet-mount in fluid from a BAL. E 4. Medical management Antihelminthic therapy: As per CDC 2020 guidelines, administer ivermectin 200 g/kg PO in a single dose for 1-2 days as first-line therapy for the treatment of patients with acute or chronic strongyloidiasis. E Show 5 more As per BIGH 2017 guidelines, administer empiric treatment without testing in patients at risk of immunosuppression, if past exposure cannot be excluded, in case of lack of adequate diagnostic facilities. B Show 2 more 5. Specific circumstances Patients with COVID-19 infection: consider administering prophylactic treatment with ivermectin in patients receiving a combination of dexamethasone and tocilizumab, coming from areas where https://web.pathway.md/diseases/recxKV1XHlJNDsQH3 2/3 6/24/23, 3:13 PM Strongyloidiasis Pathway strongyloidiasis is endemic, because the combination of dexamethasone and tocilizumab may increase the risk of opportunistic infections or reactivation. Patients with neurocysticercosis: consider screening or offering empiric therapy for Strongyloides stercoralis in patients with neurocysticercosis likely requiring prolonged corticosteroids. C 6. Follow-up and surveillance Follow-up: As per CDC 2020 guidelines, obtain follow-up stool examinations 2-4 weeks after treatment to confirm clearance of infection in patients with positive stool examination for Strongyloides and persistent symptoms. Offer retreatment if recrudescence of larvae is observed. E As per BIGH 2017 guidelines, obtain serology at baseline and repeated after 6 and 12 months after treatment to monitor the decrease in optical density/titer or negativization. B References 1. White AC Jr, Coyle CM, Rajshekhar V et al. Diagnosis and Treatment of Neurocysticercosis: 2017 Clinical Practice Guidelines by the Infectious Diseases Society of America IDSA and the American Society of Tropical Medicine and Hygiene ASTMH .1. Clin Infect Dis. 2018 Apr 3;66 8):e49-e75. Open 2. Ana Requena-M ndez, Dora Buonfrate, Joan Gomez-Junyent et al. Evidence-Based Guidelines for Screening and Management of Strongyloidiasis in Non-Endemic Countries. Am J Trop Med Hyg. 2017 Sep;97 3 645 652. Open 3. Centers for Disease Control and Prevention CDC . Parasites Strongyloides. CDC. 2020 May 26. Open 4. National Institutes of Health. Coronavirus Disease 2019 COVID 19 Treatment Guidelines. National Institutes of Health. 2021 Oct. Open https://web.pathway.md/diseases/recxKV1XHlJNDsQH3 3/3