Strongyloidiasis Treatment & Management

Updated: Nov 04, 2016
  • Author: Pranatharthi Haran Chandrasekar, MBBS, MD; Chief Editor: Michael Stuart Bronze, MD  more...
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Treatment

Approach Considerations

All persons found to harbor Strongyloides organisms should be treated, even if they are asymptomatic, because of the risk of hyperinfection. However, for infected pregnant patients, clinicians may prefer to defer treatment for strongyloidiasis until after the first trimester. All of the anthelmintic medications discussed in this article are US Food and Drug Administration (FDA) category C agents.

Strongyloides species are the hardest worms to eradicate. Treatment of early infection is with symptomatic support, because specific therapy is more effective once intestinal infection is established. Posttherapy stool examinations are recommended to verify Strongyloides eradication and to exclude other parasitic infections.

Empiric corticosteroid administration used to treat wheezing is problematic, because it may cause life-threatening hyperinfection. Thus, Strongyloides hyperinfection syndrome, usually precipitated by immune suppression, should be considered in patients who have resided in endemic regions. [66] Attempts at the detection and eradication of this infection are recommended to prevent this potentially fatal complication.

Surgical intervention may be required in the rare instance of acute abdominal symptoms (peritonitis) due to bowel obstruction or infarction in the context of severe strongyloidiasis.

Intensive care and transfer

Immunocompromised hosts may require hospitalization and intensive care in disseminated infection. Consider contact isolation in these patients, because sputum, stool, vomitus, and other bodily excreta may contain infective (filariform) larvae.

Patients with hyperinfection syndrome often have complications of sepsis, shock, and acute respiratory distress syndrome (ARDS). Any patient suspected of disseminated disease should receive care in a facility properly equipped for intensive management.

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Anthelmintic Therapy

Strongyloides infection should be suspected in a patient with nonspecific gastrointestinal, respiratory, or recurrent dermatologic symptoms of unclear etiology with risk factors for Strongyloides infection. Conduct definitive treatment with anthelmintic drugs, although these medications target adult worms and are not very effective against larvae in the initial infection.

Strongyloides infections should be treated even in the absence of symptoms as hyperinfection syndrome carries a high mortality rate. Disseminated strongyloidiasis requires treatment for at least 7 days or until the parasite can no longer be identified in clinical specimens. Concomitant infections should be treated aggressively, and any immunosuppressants, including exogenous corticosteroids, should be quickly tapered. [67] Corticosteroid therapy must be avoided, because hyperinfection and death may occur.

Anthelmintic treatment may have to be repeated or the duration prolonged in patients with hyperinfection syndrome. Relapses may occur despite proper therapy.

Anthelmintic agents

Benzimidazoles (thiabendazole, mebendazole, and albendazole) are anthelmintic agents that disrupt energy production in the parasites. The final common pathway of the benzimidazoles is inhibition of beta-tubulin polymerase, which causes disruption of cytoplasmic microtubule formation. These anthelmintics not only kill adult gut-dwelling stages of the parasite but sterilize the larvae and eggs.

Thiabendazole is the most commonly administered agent but a number of side effects makes it less desirable. Ivermectin inhibits neurotransmission in nematodes by stimulating the release of gamma-aminobutyric acid-dependent neurotransmission; eradication rates with this agent are as high as 97%.

Ivermectin and thiabendazole have shown to be superior to albendazole, and ivermectin is becoming the drug of choice in many countries due to its more favorable side effects compared with albendazole. [68, 69, 70, 25, 71] A newer drug, tribendimidine, remains under investigation in China and shows some promise in the treatment of strongyloidiasis. [72]

Patients with hyperinfection and disseminated disease should be treated with ivermectin. In this select group of patients, ivermectin should be administered daily until symptoms have resolved and until larvae have not been detected for at least 2 weeks.

Among the immunosuppressive agents, only cyclosporine A is known to possess anthelmintic activity. This was initially confirmed in animal models and subsequently observed in clinical practice. To date, no cases of severe strongyloidiasis developing in transplant recipients treated with cyclosporine have been reported.

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Antibiotic Therapy and Supportive Care

Provide antibiotic therapy directed toward enteric pathogens if bacteremia or meningitis is present or suggested; treat such bacterial complications for 2-4 weeks with antibiotics according to the results of in vitro testing against the bacterial isolate(s).

Provide supportive treatment as indicated (eg, intravenous fluids if volume depletion, blood transfusion if gastrointestinal or alveolar hemorrhage, mechanical ventilation if respiratory failure). Symptomatic treatment should be initiated. Pruritic dermatologic manifestations should be treated with antihistamines. Inhaled beta-agonists may improve wheezing; steroids should be avoided as they will worsen the infection. The use of leukotriene synthesis inhibitors for wheezing may also worsen infection, because leukotrienes are shown to play a potential role in the immunity against Strongyloides infection.

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