Testing Considerations

Gastrointestinal (GI) parasites are a lot more common in refugee patients than in the regular Canadian population. This is especially true for children from sub-Saharan Africa and Asia (DeVetten et al., 2017).

While we recommend against routine screening for GI parasites, testing should definitely be considered in any refugee patient with:

  • GI symptoms
  • Anemia
  • Eosinophilia (mainly helminths, rarely protozoa)
  • Growth problems

Screening could be considered for asymptomatic children from sub-Saharan Africa or Asia, especially those who have lived in poverty or in refugee camps.

While the clinical manifestations of each GI parasite are not covered here, keep in mind that they can cause a variety of symptoms (often mild) that can mimic other common conditions such as irritable bowel syndrome, constipation, dyspepsia or hemorrhoids (pinworm).

Traditional Ova & Parasites stool testing is not a sensitive diagnostic method, and thus repeat testing (at least 3) is recommended if a parasitic infection is suspected. In contrast, most laboratories now have access to a very sensitive polymerase chain reaction (PCR) test to screen for protozoans. It can accurately detect Giardia species, Cryptosporidium species and Entamoeba histolytica with a single sample (some assays can also detect Dientamoeba fragilis). Repeat testing is thus not necessary for this test. Unless the indication for testing is unexplained anemia or eosinophilia (in which case only Ova & Parasites testing is recommended), we usually order both screening tests when investigating a patient for potential GI parasites.

See the Helminths and Protozoans sections for the recommended first-line treatments for the most common GI parasites found in Canadian refugee patients (for uncomplicated intestinal infections only) as well as the recommended tests-of-cure.

Only our preferred first-line treatments are listed in these sections. If these regimens fail to eradicate the GI parasite in question, a referral to an Infectious Diseases specialist is suggested.

 

>> Refer to the Center for Disease Control and Prevention (CDC) website for more information on parasitic diseases.