Strongyloides stercoralis: Difference between revisions
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==Background== | ==Background== | ||
* Intestinal nematode; roundworm | * Intestinal nematode; roundworm | ||
*Endemic in tropical/subtropical areas such as Africa, Southeast Asia, Central/South America | *Endemic in tropical/subtropical areas such as Africa, Southeast Asia, Central/South America<ref>Buonfrate D, Requena-Mendez A, Angheben A, Munoz J, Gobi F, Van Den Ende J, Bisoffi Z. Severe strongyloidiasis: a systematic review of case reports. BMC Infectious Diseases 2013, 13: 78. doi:10.1186/1471-2334-13-78</ref> | ||
===Life Cycle=== | ===Life Cycle=== | ||
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==Diagnosis== | ==Diagnosis== | ||
===Clinical Presentation=== | ===Clinical Presentation=== | ||
* Asymptomatic in up to 60% of those infected | *Asymptomatic in up to 60% of those infected<ref>Greaves D, Coggle S, Pollar C, Aliyu SH, Moore EM. Strongyloides stercoralis infection. BMJ 2013;347:f4610 doi: 10.1136/bmj.f4610 (Published 30 July 2013).</ref> | ||
* Nonspecific GI complaints are most common presentation | *Nonspecific GI complaints are most common presentation | ||
** Weight loss, [[diarrhea]], [[abdominal pain]], [[vomiting]] | **Weight loss, [[diarrhea]], [[abdominal pain]], [[vomiting]] | ||
===Dermatologic=== | |||
**Larva currens: rapidly progressive pruritic linear eruption due to migration of larvae | **Larva currens: rapidly progressive pruritic linear eruption due to migration of larvae | ||
**Perianal pruritis | **Perianal pruritis | ||
**Foot pruritus (“ground itch”) | **Foot pruritus (“ground itch”) | ||
===Respiratory=== | |||
**Dry cough | **Dry cough | ||
**Wheezing | **Wheezing | ||
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====Immunocompromised patients==== | ====Immunocompromised patients==== | ||
* Respiratory and systemic | *Respiratory and systemic symptoms such as fever will be more common<ref>Lim S, Katz K, Krajden S, Fuksa M, Keystone JS, Kain KC. Complicated and fatal Strongyloides infection in Canadians: risk factors, diagnosis and management. CMAJ 2004; 171 (5): 479-484.</ref> | ||
*Disseminated disease will invade multiple organ systems, including liver and brain | *Disseminated disease will invade multiple organ systems, including liver and brain | ||
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===Immunosuppressed=== | ===Immunosuppressed=== | ||
*Combo therapy: albendazole 400 mg BID x 7d AND ivermectin 200 mcg/kg daily x 1-2d | *Combo therapy: albendazole 400 mg BID x 7d AND ivermectin 200 mcg/kg daily x 1-2d<ref name="treat">Feely NM, Waghorn DJ, Dexter T, Gallen I, Chiodini. Strongyloides stercoralis hyperinfection: difficulties in diagnosis and treatment. Anaesthesia 2010; 65: 298-301.</ref> | ||
* | *Antibiotics may need to be continued until there is evidence that parasite is cleared<ref name="treat"></ref> | ||
==Disposition== | ==Disposition== | ||
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==Sources== | ==Sources== | ||
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Revision as of 22:22, 18 March 2015
Background
- Intestinal nematode; roundworm
- Endemic in tropical/subtropical areas such as Africa, Southeast Asia, Central/South America[1]
Life Cycle
- Present in contaminated soil => larvae penetrate skin of hosts walking barefoot => enter venous circulation, migrate to lungs, then are expectorated to pharynx and swallowed => larvae develop into females that lay eggs asexually into GI tract, which hatch into larvae and are excreted into stool
- Larvae either become sexually reproducing males/females or filariform larvae that can reinfect host
- Autoinfection: Unique to Strongyloides; GI larvae can migrate from GI tract to venous system, then to lungs and proceed with life cycle
- Can lead to dramatic increase in worm burden and hyperinfection in immunocompromised
Risk factors
- Corticosteroid use, immunosuppression
- Transplantation
- Hematologic neoplasm
- Human T-lymphotropic virus-1 infection (HTLV-1)
- Malnutrition
- Diabetes
- Chronic renal failure
- Chronic alcohol use
Clinical significance
- Chronic infection in immunosuppressed can lead to fulminant dissemination with case fatality rate as high as 70%; strong index of suspicion is needed in such cases
Diagnosis
Clinical Presentation
- Asymptomatic in up to 60% of those infected[2]
- Nonspecific GI complaints are most common presentation
- Weight loss, diarrhea, abdominal pain, vomiting
Dermatologic
- Larva currens: rapidly progressive pruritic linear eruption due to migration of larvae
- Perianal pruritis
- Foot pruritus (“ground itch”)
Respiratory
- Dry cough
- Wheezing
- Loeffler’s-like syndrome: fever, SOB, wheezing, pulmonary infiltrates
Immunocompromised patients
- Respiratory and systemic symptoms such as fever will be more common[3]
- Disseminated disease will invade multiple organ systems, including liver and brain
Differential Diagnosis
- Inflammatory bowel disease
- Schistosomiasis
- Filariasis
- Hookworm
- Toxocara canis
- Atopic dermatitis
- Asthma
- Allergic bronchopulmonary aspergillosis
- Coccidioidomycosis
- HIV
- Churg-Strauss syndrome
- Eosinophilic leukemia]
Work-Up
- High index of suspicion, good travel history
Labs
- Notable eosinophilia in up to 70% of cases, though can be absent in immunosuppressed
- Gram negative bacteremia may be present in immunocompromised
- Uncomplicated strongyloidiasis: 3 serial stool samples screened for ova and parasites, as well as ELISA for Strongyloides
- Complicated strongyloidiasis: blood/sputum Cx, in addition to above
Treatment
Uncomplicated strongyloidiasis, normal immune system
- Albendazole 400 mg BID x 7d
- OR
- Ivermectin 200 mcg/kg daily x 1-2d (drug of choice)
- Can consider albendazole prophylaxis in immigrants from endemic regions with consistent clinical presentation
Immunosuppressed
- Combo therapy: albendazole 400 mg BID x 7d AND ivermectin 200 mcg/kg daily x 1-2d[4]
- Antibiotics may need to be continued until there is evidence that parasite is cleared[4]
Disposition
- Often diagnosed in outpatient setting, can discharge uncomplicated cases in those who are not immunosuppressed
- Immunocompromised patients or those with systemic symptoms will require admission
Sources
- ↑ Buonfrate D, Requena-Mendez A, Angheben A, Munoz J, Gobi F, Van Den Ende J, Bisoffi Z. Severe strongyloidiasis: a systematic review of case reports. BMC Infectious Diseases 2013, 13: 78. doi:10.1186/1471-2334-13-78
- ↑ Greaves D, Coggle S, Pollar C, Aliyu SH, Moore EM. Strongyloides stercoralis infection. BMJ 2013;347:f4610 doi: 10.1136/bmj.f4610 (Published 30 July 2013).
- ↑ Lim S, Katz K, Krajden S, Fuksa M, Keystone JS, Kain KC. Complicated and fatal Strongyloides infection in Canadians: risk factors, diagnosis and management. CMAJ 2004; 171 (5): 479-484.
- ↑ 4.0 4.1 Feely NM, Waghorn DJ, Dexter T, Gallen I, Chiodini. Strongyloides stercoralis hyperinfection: difficulties in diagnosis and treatment. Anaesthesia 2010; 65: 298-301.