Strongyloides and Schistosoma

See Intestinal parasites – Strongyloides and Schistosoma: evidence review for newly arriving immigrants and refugees.

  • Strongyloidiasis: Screen refugees newly arriving from Southeast Asia and Africa with serology for strongyloidiasis and treat if positive with ivermectin (first line) or albendazole (if contraindications to ivermectin - see table below).
  • Schistosomiasis: Screen refugees newly arriving (i.e. within five years) from Africa with serology for schistosomiasis and treat if positive with praziquantel (40mg/kg divided BID for one day; covered by IFH)
  • Strongyloidiasis and schistosomiasis can persist as sub-clinical infection for years.
  • Eosinophilia may offer indirect evidence of strongyloidiasis or schistosomiasis. 
  • CDC's DPDx describes clinical features of strongyloidiasis and schistosomiasis.
  • Ivermectin can be obtained through Health Canada’s Special Access Programme. Request Form here. Stromectol monograph with dosing by weight here. Physician sends in the request form, and Health Canada sends it on to the manufacturer (Merck). Merck sends the physician a second form. When that form is submitted and approved, the tablets are sent to the physician's office.
  • Individuals with strongyloidiasis from Loa loa endemic areas (see table below) should either (i) be tested for microfilaremia prior to treatment with ivermectin or (ii) be treated with albendazole. Flowchart developed by Dr. Josee Poulin here
  • Consider post-treatment serologic testing for strongyloidiasis, especially if sx/eosinophilia persist 6/12 post treatment.
  Eggs of  Schistosoma haematobium   surrounded by intense infiltrates of eosinophils and other inflammatory cells. CDC/Dr. Edwin P. Ewing, Jr., 1973.

Eggs of Schistosoma haematobium surrounded by intense infiltrates of eosinophils and other inflammatory cells. CDC/Dr. Edwin P. Ewing, Jr., 1973.

Per Intestinal parasites – Strongyloides and Schistosoma: evidence review for newly arriving immigrants and refugees from Canadian Guidelines on Immigrant Health. July 2011:

"A two-day course of ivermectin (200 µg/kg orally once daily) is the preferred treatment strategy for strongyloidiasis, however among refugees from Loa loa endemic areas of the world, a seven-day course of albendazole (400 mg orally twice daily) should be used."

Per the CDC Overseas Refugee Health Guidelines: Intestinal Parasites

African countries NOT endemic for Loa loa

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African countries endemic for Loa loa

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   Strongyloides  filariform larva.  CDC/Dr. Mae Melvin. 1974.

Strongyloides filariform larva. CDC/Dr. Mae Melvin. 1974.

Reviewed/updated by Martina Scholtens MD CCFP (September 29, 2015)