Treatment algorithm

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

INITIAL

immigrant from endemic area

1st line – screening for serological strongyloides IgG or empirical ivermectin

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INITIAL
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immigrant from endemic area
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with unexplained eosinophilia
1st line – 

screening for serological strongyloides IgG or empirical ivermectin

When unexplained eosinophilia is detected in any person who has migrated from an endemic area, screening for serological strongyloides infection is required. In the US, asymptomatic refugees who did not receive overseas presumptive ivermectin therapy for strongyloides may be presumptively treated upon arrival, or screened (using strongyloides IgG serology) if there are contraindications to presumptive treatment (e.g., concomitant Loa loa infection) or if ivermectin is unavailable.[37] Stool ova and parasite examination should not be used to rule out infection, as it lacks sensitivity for Strongyloides infection. Refugees who have lived in Loa loa-endemic countries should be tested for Loa loamicrofiliariaemia before being treated with ivermectin in order to prevent complications, including encephalopathy. Presumptive treatment for pregnant women is not recommended.[37] 

Primary options

ivermectin: children <15 kg body weight: consult specialist for guidance on dose; children and adults ≥15 kg body weight: 0.2 mg/kg orally as a single dose for 1-2 days

1st line – screening for serological strongyloides IgG or empirical ivermectin

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INITIAL
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immigrant from endemic area
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immunosuppressant therapy commencing or planned
1st line – 

screening for serological strongyloides IgG or empirical ivermectin

Risk of life-threatening hyperinfection is primarily related to immunosuppression, particularly the iatrogenic introduction of corticosteroid (or other immunosuppressive) therapy for a comorbid disorder.[20][21]

Empirical treatment with ivermectin is most likely necessary with iatrogenic immunosuppression although serological screening for infection can be pursued if time allows before immunosuppression commences.

Empirical ivermectin is required when starting immunosuppressive therapy, such as in the case of severe asthma or COPD, especially if there is eosinophilia.[11]

For planned future immunosuppression, such as anticipated organ or bone marrow transplantation, screening should be performed as part of the pre-transplant evaluation.

If a woman is pregnant, screening should be performed before treatment. In this situation consultant advice should be sought.

Primary options

ivermectin: children <15 kg body weight: consult specialist for guidance on dose; children and adults ≥15 kg body weight: 0.2 mg/kg orally as a single dose for 1-2 days

ACUTE

able to tolerate oral therapy: not critically ill (nonpregnant)

1st line – oral anthelmintic

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ACUTE
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able to tolerate oral therapy: not critically ill (nonpregnant)
1st line – 

oral anthelmintic

Ivermectin is the drug of choice for strongyloides infection. It is well-tolerated and has greater efficacy than albendazole.[38] [ Cochrane Clinical Answers logo ] [Evidence B]​​ Ivermectin may not be available in all regions, so albendazole is a suitable alternative. The failure rate of 7 days of albendazole is 20% to 40%,[39][40][42][44][45] so it should only be used if there is no alternative.[1]

Various treatment regimens exist and local guidance should be consulted. The US Centers for Disease Control and Prevention (CDC) recommends 1-2 doses of ivermectin administered on consecutive days.[48]​ The efficacy of one dose of ivermectin has been directly compared with two doses separated by 2 weeks in a randomised trial without any difference found.[46]

Ivermectin may very rarely precipitate encephalitis in people who have concomitant heavy infection with Loa loa, due to the mass killing of microfilariae in the central nervous system. This is becoming more of a theoretical concern, due to the success of the ongoing river blindness (onchocerciasis) eradication programmes led by the Carter Center, which uses ivermectin. However, should current eradication programmes break down (e.g., in situations such as long-term war), people should then be screened first for filariasis by blood smear collected between 10 a.m. and 2 p.m, before receiving ivermectin.[28]

Moxidectin is another possible alternative. It has been approved by the US Food and Drug Administration (FDA) for onchocerciasis. It has a long history of use in veterinary medicine and may be used off-label for strongyloides. Moxidectin had a 94% cure rate for strongyloides in one randomised trial, which was similar to the 95% cure rate of ivermectin.[47] As it has a long half life in tissue, a single dose is effective. Moxidectin has not been studied in children aged <12 years. If ivermectin is unavailable, moxidectin may be the preferred alternative as albendazole is clearly inferior to ivermectin.

Primary options

ivermectin: children <15 kg body weight: consult specialist for guidance on dose; children and adults ≥15 kg body weight: 0.2 mg/kg orally as a single dose for 1-2 days

Secondary options

moxidectin: children ≥12 years of age and adults: 8 mg orally as a single dose

OR

albendazole: children: consult specialist for guidance on dose; adults: 400 mg orally twice daily for 3-7 days

unable to tolerate oral therapy or critically ill (nonpregnant)

1st line – parenteral or rectal ivermectin

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ACUTE
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unable to tolerate oral therapy or critically ill (nonpregnant)
1st line – 

parenteral or rectal ivermectin

Treatment should be supervised by a tropical medicine specialist.

If people are critically ill with hyperinfection or disseminated infection, and unable to consume or absorb oral medicines, alternative delivery via subcutaneous, intravenous, or rectal routes is necessary.

Veterinary preparations of ivermectin are available for intravenous, subcutaneous or rectal use. These are not approved for human use, but the veterinary formulations can be life-saving and have been used.

Treatment duration is 7-14 days in hyperinfection or disseminated strongyloidiasis. Switch to oral therapy when possible.

Alternatively, ivermectin and albendazole have been administered together for this indication.[49]

pregnant

1st line – delay anthelmintic therapy until after pregnancy

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ACUTE
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pregnant
1st line – 

delay anthelmintic therapy until after pregnancy

Treatment should be supervised by a tropical medicine consultant.

In chronic strongyloides infection, deferring treatment until after pregnancy is reasonable. However, in hyperinfection or disseminated strongyloidiasis, therapy should be given immediately.

Data on ivermectin and albendazole use in pregnancy is sparse, but no increased teratogenicity has been reported with inadvertent use in the first trimester during lymphatic filariasis eradication programmes.[50]

If corticosteroids are required to accelerate fetal lung development, specialist advice should be sought.

ONGOING

poor clinical response or initial treatment not completed

1st line – re-treatment with anthelmintic + screen for immunosuppressive condition

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ONGOING
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poor clinical response or initial treatment not completed
1st line – 

re-treatment with anthelmintic + screen for immunosuppressive condition

People not completing a treatment course, whether due to intolerance, non-compliance, or other reasons, should be given re-treatment.

Two doses of ivermectin are generally well-tolerated and are approximately 85% to 95% effective.[42][43][44][45][46]

If there is a persistent eosinophilia of more than 4-6 months duration following treatment, treatment failure is highly probable.[11][33] Re-treatment is required with ivermectin and consideration of screening for human T-cell lymphotropic virus type-1 (HTLV-1) infection.[23] Albendazole is a suitable alternative.

Moxidectin is another possible alternative. It has been approved by the US Food and Drug Administration for onchocerciasis. It has a long history of use in veterinary medicine and may be used off-label for strongyloides. Moxidectin had a 94% cure rate for strongyloides in one randomised trial, which was similar to the 95% cure rate of ivermectin.[47] As it has a long half life in tissue, a single dose is effective. Moxidectin has not been studied in children aged <12 years . If ivermectin is unavailable, moxidectin may be the preferred alternative as albendazole is clearly inferior to ivermectin.

Primary options

ivermectin: children <15 kg body weight: consult specialist for guidance on dose; children and adults ≥15 kg body weight: 0.2 mg/kg orally as a single dose for 1-2 days, may repeat in 2-4 weeks if necessary

Secondary options

moxidectin: children ≥12 years of age and adults: 8 mg orally as a single dose

OR

albendazole: children: consult specialist for guidance on dose; adults: 400 mg orally twice daily for 3-7 days

2nd line – intensive anthelmintic therapy

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ONGOING
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poor clinical response or initial treatment not completed
2nd line – 

intensive anthelmintic therapy

In immunosuppressed people, such as those with human T-cell lymphotropic virus type-1 (HTLV-1) infection or AIDS, multiple 14-day treatment courses separated by 2-week intervals may be necessary.

In immunosuppressed people, follow-up stool ova and parasite examinations to verify eradication of strongyloides at 3 and 6 months is recommended.

In 65% to 80% of people, the quantitative serology will decrease by 40% or become negative after 6 months.[52] A lack of more than 40% decrease in serology or an increase should prompt re-treatment.[53]

Primary options

ivermectin: children <15 kg body weight: consult specialist for guidance on dose; children and adults ≥15 kg body weight: 0.2 mg/kg orally once daily for 2 weeks; repeat at 2-week intervals until infection is eradicated

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Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer

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