Worldwide prevalence of SI may be as high as 100 million people, with an increasing number seen in developed countries among immigrants (including those from Latin America), refugees, and travelers. “Autoinfection” by Strongyloides allows it to complete its life cycle between the GI tract and the lung without leaving the host, and is often associated with chronic asymptomatic infection in the immunocompetent persons1.
Immunocompromised patients, however, particularly those treated with corticosteroids (including systemic courses as short as 6 days, or local injection) are at increased risk of developing an accelerated form of autoinfection due to SI, also known as hyperinfection syndrome (HIS)1,2. HIS has been reported as late as 64 years after leaving an endemic area!1. When Strongyloides larvae disseminate away from the lung or GI tract into other organs (e.g. brain) the mortality rate may approach 100%, if untreated.
Due to the potential complications associated with untreated SI, particularly in the immunocompromised , routine screening of anyone with a potential Strongyloides-exposure history (irrespective of symptoms or years since exposure) has been advocated1,3. In our patient with COPD, screening for asymptomatic SI by a highly sensitive test (eg serology) should be considered (as early as possible if corticosteroids are being considered for treatment of his COPD). Some have also advocated empiric treatment with ivermectin in “at risk patients” in whom testing is not feasible or practical1,4.
Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!
References
- Mejia R, Nutman TB. Screening, prevention, and treatment for hyperinfection syndrome and disseminated infections caused by Strongyloides stercoralis. Curr Opin Infect Dis 2012;25:458-463.
- Keiser PB, Nutman TB. Strongyloides stercoralis in the immunocompromised population. Clin Microbiol Rev 2004;17:208-217.
- CDC. Strongyloides. http://www.cdc.gov/parsites/strongyloides/helath_professionals/ , accessed September 20, 2016.
- Santiago M, Leitão B. Prevention of strongyloides hyperinfection syndrome: a rheumatologic point of view. Eur J Intern Med 2009;20:744-748.
Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!
