LAUSR

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: The presentation of fever, fatigue, myalgias, and acute hypoxemic respiratory failure is COVID-19 viral pneumonia until proven otherwise. However, findings like rash, photophobia, and unexplained lab abnormalities suggest an alternate diagnosis. We present a case of flea-borne (murine) typhus, causing acute illness with increasing prevalence in southern Texas and California. CASE PRESENTATION: In April 2020, a 32-year-old male presented to our emergency department (ED) with one week of fever, headache, progressive dyspnea, myalgias, and flank pain. Five days prior, COVID-19 PCR was negative;he was diagnosed with bilateral pneumonia on CT chest tomography and prescribed azithromycin. In the ED, he was found to be in acute hypoxemic respiratory failure needing high flow oxygen support prompting ICU admission. Vital demonstrated temperature of 103.4 degrees, heart rate of 130, respiratory rate of 26, and Spo2 of 96% oxygen saturation on 10L non-rebreather mask;Physical exam demonstrated dry mucous membranes, conjunctivitis, and labored respirations with accessory muscle use. Labs revealed hyponatremia, elevated liver function tests, hypoalbuminemia, thrombocytopenia, and elevated lactate dehydrogenase and procalcitonin. Repeat CT chest tomography showed posterior lower lobe opacities and concomitant ground glass opacities suggestive of atypical infection. Negative workup included two COVID-19 nasopharyngeal swabs, influenza A/B, RSV, HIV, streptococcus pneumoniae, and legionella urine antigen. He admitted recent travel to the Louisiana Gulf Coast with exposure to horses, chickens, and insect bites on the arm on further questioning. Vancomycin, ceftriaxone, and doxycycline were started on hospital day 2. A papular rash appeared on the lower back on hospital day 6. He still remained febrile and with significant hypoxemia for seven days. On day 9, Rickettsial typhus serologies returned IgM 1:512, and repeat tests confirmed both elevated IgM and IgG. The patient tapered off oxygen and was discharged home on doxycycline. DISCUSSION: Many cases of murine typhus are assumed to be a viral illness, but the clinical triad of fever, headache, and rash in endemic areas must raise suspicion. The exposure was likely insect bites (fleas), although it is not necessary, as endemic typhus has been identified in rural/suburban areas from possums, rats, or cats. In the COVID-19 pandemic, murine typhus with fever and acute hypoxemic respiratory failure was challenging to identify, but early diagnosis and treatment with tetracyclines provided a good outcome. CONCLUSIONS: The presentation of fever, headache, and rash with thrombocytopenia and transaminitis should trigger typhus workup and early treatment, which may otherwise progress to critical illness and death. REFERENCE #1: Afzal Z, Kallumadanda S, Wang F, Hemmige V, Musher D. Acute Febrile Illness and Complications Due to Murine Typhus, Texas, USA1,2. Emerg Infect Dis. 2017;23(8):1268-1273. doi:10.3201/eid2308.161861 REFERENCE #2: van der Vaart TW, van Thiel PP, Juffermans NP, van Vugt M, Geerlings SE, Grobusch MP, Goorhuis A. Severe murine typhus with pulmonary system involvement. Emerg Infect Dis. 2014 Aug;20(8):1375-7. doi: 10.3201/eid2008.131421. PMID: 25062435;PMCID: PMC4111165. DISCLOSURES: No relevant relationships by Philip Lavere, source=Web Response No relevant relationships by Dharani Kumari Narendra, source=Web Response