Common Gastrointestinal Parasites in Refugee Patients
Overview
Gastrointestinal parasites are significantly more common in refugee patients than in the general Canadian population, especially in children from sub-Saharan Africa and Asia.
When to test: GI symptoms, unexplained anemia, eosinophilia, growth problems in children.
Testing: Order both Stool Ova and Parasites (at least 3 samples) and Protozoal Screen PCR (single sample, highly sensitive for Giardia, Cryptosporidium, and E. histolytica).
Always complete the CLS Stool and Parasite History Form when ordering stool tests.
Helminths
Ascaris lumbricoides
* Treatment: Mebendazole 500 mg once, or 100 mg twice daily for 3 days (age 2 and older)
* Test-of-cure: Stool O and P 3 months post-treatment
Enterobius vermicularis (Pinworm)
* Symptoms: Perianal itching worse at night
* Treatment: Mebendazole 100 mg once, repeated in 2 weeks (age over 2). Treat entire household if more than one person is infected.
* Test-of-cure: Not needed unless symptoms persist
Hookworms (Ancylostoma / Necator)
* Treatment: Mebendazole 500 mg once, or 100 mg twice daily for 3 days (age 2 and older)
* Test-of-cure: Stool O and P 1 month post-treatment
Trichuris trichiura (Whipworm)
* Treatment: Mebendazole 100 mg twice daily for 3 days (age 2 and older)
* Test-of-cure: Stool O and P 1 month post-treatment
Hymenolepis nana
* Treatment: Praziquantel 25 mg/kg as a single dose, repeated 10 days later
* Test-of-cure: Stool O and P 1 month post-treatment
Taenia saginata/solium (Intestinal Tapeworms)
* Treatment: Praziquantel 5-10 mg/kg as a single dose
* Test-of-cure: Stool O and P 1 month post-treatment
Does not treat cysticercosis (larval stage of T. solium)
Protozoa
Giardia lamblia
* Treatment (1st line): Metronidazole 500 mg twice daily for 7 days (children: 15 mg/kg/day divided in 3 doses for 7 days, max 250 mg/dose)
* Treatment (2nd line): Mebendazole 200 mg three times daily for 5 days (age over 2)
* Test-of-cure: Protozoal Screen 1 month post-treatment
* Treat asymptomatic children (impacts growth)
Entamoeba histolytica
Treat even if asymptomatic (risk of invasive disease).
* Symptomatic: Metronidazole 750 mg three times daily for 10 days, THEN Paromomycin 25-35 mg/kg/day divided in 3 doses for 7 days
* Asymptomatic: Paromomycin only
* Test-of-cure: Protozoal Screen 1 month post-treatment
Entamoeba dispar does not require treatment.
Blastocystis hominis / Dientamoeba fragilis
Treat only if symptomatic.
* Treatment: Metronidazole 750 mg three times daily for 10 days
* Test-of-cure: Re-test only if still symptomatic
Cryptosporidium
* Usually self-limited in immunocompetent patients. Supportive care only.
* For immunocompromised patients or severe cases: consult Infectious Diseases. Always rule out HIV.
Calgary Resources
* Praziquantel and paromomycin can usually be obtained at Lukes Drug Mart, Bridgeland
* For treatment failures: Tropical Infectious Diseases Clinics Calgary