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