Strongyloides stercoralis in the immunocompromised population

Abstract

Blood Marrow Transplant (BMT) patients are typically immunocompromised for prolonged periods. Due to a compromised immune system, BMT patients are susceptible to acquiring opportunistic infections. Infectious organisms may include parasites such as Toxoplasma gondii, Pneumocystis carinii, Entamoeba coli, and more infrequently Strongyloides stercoralis. Strongyloides stercoralis is an intestinal nematode of humans estimated affecting tens of millions of persons worldwide. This parasite is endemic in tropical or temperate and subtropical climates. Risk factors may include travel to those areas. S. stercoralis can transform into a fulminant fatal illness in certain conditions associated with a compromised host. With the increased mortality and morbidity associated with S. stercoralis focusing on identifying, screening, and treating those at risk is warranted. Of the individuals who are infected with S. stercoralis, 50% are asymptomatic and 75% manifest eosinophilia. Clinical symptoms include epigastric pain and tenderness, diarrhea, nausea and vomiting, constipation, and weight loss. In BMT patients, there may be an acceleration of the autoinfection cycle which can result in hyperinfection syndrome and/or disseminated strongyloidiasis increasing the high probability of multi-organ system invasion. Treatment goals of patients with S. stercoralis are directed toward preventing hyperinfection and dissemination, as well as complete eradication. Three oral preparations are available for use in uncomplicated intestinal strongyloidiasis, these include: thiabendazole, albendazole, and ivermectin. Multi-dose scheduled regimens may be necessary. Educational opportunities should focus on increasing clinician’s knowledge about clinical manifestations, diagnosis/pathogenesis, and treatment of this infrequent infection to facilitate earlier recognition of and/or surveillance for infection in high-risk patients. A case study of a BMT patient will be presented.