SUCCESSFUL USE OF EXTRACORPOREAL MEMBRANE OXYGENATION IN MURINE TYPHUS COMPLICATED BY ARDS

Abstract

SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Murine typhus is a flea-borne disease caused by the bacteria Rickettsia typhi. Presentations are widely variable. Critical illness occurs rarely and mortality occurs in less than 1% of patients who receive treatment. We present a case of a patient with acute respiratory distress syndrome (ARDS) secondary to murine typhus successfully temporized with extracorporeal membrane oxygenation (ECMO). CASE PRESENTATION: A 37 year-old man with no past medical history presented with fever (40◦c), headache, weakness, dizziness, and septic physiology. Initial chest imaging was unremarkable. Labs revealed leukopenia, thrombocytopenia, and elevation in liver associated enzymes. Broad spectrum antibiotics were initiated. The following day, he developed shortness of breath and cough which progressed to frank hemoptysis. He was intubated for hypoxic respiratory failure and serial imaging revealed rapidly progressive ARDS. Doxycycline was added. Within 24 hours, hypoxemia and acidosis were refractory to lung protective ventilation strategies and he was cannulated for veno-venous ECMO. His course was complicated by acute renal insufficiency, septic shock, septic cardiomyopathy, and delirium. An exhaustive work-up revealed a high R. typhi IgM titer (1:1024), consistent with acute infection. His work-up was otherwise unremarkable. He rapidly improved, was weaned from pressor support, decannulated from ECMO, and liberated from the ventilator. After extubation, the patient reported regularly feeding stray cats. He completed a 10 day course of doxycycline 100mg twice daily and was discharged home to make a full recovery. DISCUSSION: In the United States, Murine Typhus is endemic to Texas, California, and Hawaii(1). Sporadic cases occur worldwide. Rat fleas (Xenopsylla cheopis) are the classic vector. In the United States, the flea (Ctenocephalides felis) from cats and opossums are also responsible. Disease occurs when an infected flea bites and then stools in the wound(1). Incidence in Texas is 59.5 cases per 100,000(2), but may be more common and misdiagnosed(3). The classic triad of fever, headache, and rash only occurs in a third of patients(3). Flea exposure, elevated liver associated enzymes and thrombocytopenia offer diagnostic clues(3). Once suspected, empiric doxycycline is recommended; however, care is often supportive(1). While mostly indolent, critical illness occurs rarely. Risk factors for severe disease include immunosuppressed state, advanced age, and glucose-6-phosphate dehydrogenase deficiency(3). Without any risk factors, it is unclear why our patient experienced such a complicated course and ultimately required ECMO for respiratory support. CONCLUSIONS: To our knowledge, this case represents the first reported use of ECMO to support a patient with ARDS secondary to Murine typhus and demonstrates the use of ECMO for supportive care in a limiting illness. Reference #1: Civen R, Ngo V. Murine Typhus: An Unrecognized Suburban Vectorborne Disease, Clinical Infectious Diseases, Volume 46, Issue 6, 15 March 2008, Pages 913–918, https://doi.org/10.1086/527443 Reference #2: Murray KO, Evert N, Mayes B, et al. Typhus Group Rickettsiosis, Texas, USA, 2003-2013. Emerg Infect Dis. 2017;23(4):645-648. Reference #3: Tsioutis C, Zafeiri M, Avramopoulos A, et al. Clinical and Laboratory Characteristics, Epidemiology, and Outcomes of Murine Typhus: A Systematic Review, Acta Tropica, Volume 166, 7 February 2017, Pages 16-24, https://doi.org/10.1016/j.actatropica.2016.10.018 DISCLOSURES: No relevant relationships by Daniel Foster, source=Web Response No relevant relationships by Michael Gonzales, source=Web Response No relevant relationships by Chungting Kou, source=Web Response No relevant relationships by Justin Reis, source=Web Response