JOURNAL OF THE LOUISIANA STATE MEDICAL SOCIETY
therapy for exacerbation of SLE, the patient developed an acute surgical abdomen and underwent right hemicolectomy for internal bleeding. 22 Numerous filariform larvae were identified microscopically throughout the colon surgical specimen and in a lung biopsy. 22 The patient then developed diffuse alveolar hemorrhage causing acute respiratory distress syndrome. 22 Following3weeks of treatmentwith ivermectinandalbendazole, the patient recovered, demonstrated repeated negative stool specimens for Strongyloides larvae, and was discharged to long- term care on hospital day 60. 22 In a 2009 review of preventive strategies for Strongyloides hyperinfection in immunosuppressed patients with rheumatological disorders, Santiago and Leitão identified two articles on the prophylaxis of hyperinfection in immunosuppressed patients and 13 studies recommending different therapeutic options for patients with chronic strongyloidiasis. 23 The authors failed to identify any studies specifically restricted to immunosuppressed patients with rheumatic diseases. 23 Based on their review of the scientific literature, however, the authors recommended administering ivermectin, 200 µg/kg orally for two days and repeated every two weeks at six month intervals to immunosuppressed patients with autoimmune rheumatic disorders under therapy with corticosteroids and residing permanently in areas of Strongyloides endemicity. 23 Given the low sensitivity of traditional laboratory tests, such as direct microscopy, parasite culture, and serology, in detecting Strongyloides larvae in stool specimens, the most important preventive strategies for strongyloidiasis and its potentially lethal complications of hyperinfection and dissemination should include the following: (1) early recognition of risk factors for strongyloidiasis, such as wartime service, ex-POW status, or prolonged remote and rural travel in Southeast Asia; (2) empiric treatment with ivermectin based on clinical presentation and immunocompetency status, even if unsupported by positive screening microscopy and serological tests for strongyloidiasis; and (3) consideration of prophylactic ivermectin therapy at the CDC-recommended therapeutic doses of 200 µg/kg, orally for one-to-two days in high-risk and/or immunosuppressed patients who have ever lived or traveled extensively in disease- endemic countries, especially prior to initiating corticosteroid therapy.
The Treatment of Strongyloidiasis
According to the CDC, the first line therapy for both acute and chronic strongyloidiasis is with ivermectin in a single dose, 200 µg/kg orally for one-to-two days. 20 Relative contraindications include confirmed or suspected concomitant Loa loa infections, weight less than 15 kg, and pregnancy and lactation. Alternative therapy is with albendazole, 400 mg orally, twice a day for seven days. Relative contraindications include the first trimester of pregnancy and hypersensitivity to benzimidazole compounds. In cases of hyperinfection syndrome and disseminated strongyloidiasis, all immunosuppressive therapy should be stopped or at least reduced, if possible; and followed by ivermectin, 200 µg/kg, orally every day until stool and/or sputum exams are negative for Strongyloides larvae for two weeks. 20 For patients who cannot tolerate ivermectin and for those with malabsorption, ileus, or intestinal obstruction, ivermectin can be administered rectally at the same doses. In all cases, any sub-optimal response or non-response to anti-helminthic therapy with either ivermectin or albendazole should prompt a diagnostic work-up for HTLV-1, another independent risk factor for Strongyloides hyperinfection. 13
The Prevention and Control of Strongyloidiasis
Although sunbathing on beach towels and wearing shoes or sandals while walking on tropical beaches and when using outdoor public toilets will prevent skin invasion by soil- transmitted nematodes, many tourists and immigrants visiting friendsandrelativesoftenignorethesesimplerecommendations. In addition, many physicians do not include strongyloidiasis in their differential diagnosis of fever, dry cough, and migratory urticaria in returning travelers. In 2007, Boulware and coinvestigators conducted a survey among resident physicians worldwide, and only 9% recognized theneedforparasitic screening inahypothetical caseof imported strongyloidiasis in a returning traveler. 21 Even more concerning, 23% of the resident physician respondents recommended a course of oral corticosteroids for a hypothetical case presenting with dry cough, wheezing, and peripheral eosinophilia designed to mimic Loeffler’s syndrome. 21 Such a course of management could have precipitated hyperinfection and potentially fatal disseminated strongyloidiasis, especially in a patient with pre-existing immunosuppression by autoimmune disease, malignancy, or HTLV-1. The authors concluded that there was a significant inability of young physicians to recognize the risk factors for and the potential life-threatening complications of strongyloidiasis. 21 In 2014, Yung and coauthors confirmed these earlier predictions by reporting the case of a 30-year-old Hispanic man with undiagnosed chronic strongyloidiasis treated with methylprednisolone for systemic lupus erythematosus (SLE) who subsequently developed hyperinfective and disseminated strongyloidiasis. 22 On the day after initiating corticosteroid
CONCLUSIONS
Clinicians need to include strongyloidiasis in the differential diagnosis of fever, urticaria, and cough in travelers returning from Strongyloides -endemic regions of the tropics and subtropics and to recognize the risk factors for and the potential life-threatening complications of strongyloidiasis, especially in Vietnam War veterans and ex-POWs. Given the inadequacies of microscopic screening for strongyloidiasis and the serious outcomes of Strongyloides hyperinfection and dissemination, clinicians should consider the presumptive treatment of high-risk patients with safe and effective drugs, such as ivermectin preferably,
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