UNDERSTANDING THE NEED FOR A BROAD DIFFERENTIAL DIAGNOSIS: A CASE OF PNEUMONIC TULAREMIA

ABSTRACT

SESSION TITLE Disseminated Bacterial Infections SESSION TYPE Rapid Fire Case Reports PRESENTED ON 10/18/2022 1015 am - 1110 am INTRODUCTION: Tularemia is a rare infectious disease caused by Francisella Tularensis that typically affects the skin, eyes, lymph nodes, and lungs. There are a variety of forms of tularemia with varying rates of contagiousness and mortality. Respiratory tularemia has a high mortality rate if left untreated and presents with non-specific viral like symptoms occurring in conjunction with respiratory symptoms cough, hemoptysis, and pleuritic chest pain. In this COVID ARDS era, it is important to evaluate a broad differential diagnosis. Therefore, the authors describe a patient presenting with flu-like respiratory symptoms whom was ultimately was diagnosed with acute respiratory distress syndrome (ARDS) due to F. Tulerensis. CASE PRESENTATION A 44-year-old male presented with a four-day history of night sweats, shortness of breath, a productive cough which progressed to hemoptysis, and oliguria. Prior to admission, his initial symptoms were treated as chronic sinusitis with varied antibiotics. Social history including tobacco abuse and deer hunting 1 month prior to presentation. Vitals were stable except for tachycardia, hypoxia, and tachypnea. Laboratory findings were significant for AKI, lactic acidosis, mild transaminitis, hyperbilirubinemia, and leukocytosis with predominant neutrophilia. Thoracic CTA showed bilateral diffused pulmonary edema without evidence of pulmonary embolism. Due to the patient's worsening respiratory status, he was intubated for support. The patient progressed to Severe ARDS per Berlin Criteria eventually requiring pronation and continuous paralyzing. Bronchoscopy was performed with bronchial lavage. Bacterial, viral, and fungal cultures did not show growth while vasculitic work-up was negative. Empiric antibiotic treatment did not show improvement until the patient was diagnosed with F. Taularensis via serological testing with an IgM of 20 U/mL, and patient was transitioned to gentamycin. Ultimately, the patient was extubated, transitioned to oral doxycycline, and discharged home. DISCUSSION: Approximately 250 cases of tularemia are reported to CDC each year. Respiratory tularemia has a mortality rate up to 30% if not treated. For this reason, F. tularensis is a potential biological weapon and is categorized as a Group A pathogenic agent. Serological testing may be negative early in disease progression;therefore, early inflammatory markers with clinical suspicion are essential to diagnose the disease early in its course. DNA microarray has high specificity and sensitivity for rapid diagnosis of tularemia while being cost effective. After prompt diagnosis, intravenous aminoglycosides;such as gentamycin or streptomycin;must be started. CONCLUSIONS: In the above case, we illustrate the gradual onset and rapid patient deterioration when treatment is delayed;yet, there is rapid recovery once appropriate treatment is used. Reference #1 1. Ranjbar, Reza, Payam Behzadi, and Caterina Mammina. "Respiratory tularemia Francisella tularensis and microarray probe designing.” The open microbiology journal 10 (2016) 176. Reference #2 2. Akhvlediani, N., I. Burjanadze, D. Baliashvili, T. Tushishvili, M. Broladze, A. Navdarashvili, S. Dolbadze et al. "Tularemia transmission to humans a multifaceted surveillance approach.” Epidemiology & Infection 146, no. 16 (2018) 2139-2145. Reference #3 3. Tularemia in British Columbia A case report and review. Issue BCMJ, vol. 52, No. 6, July August 2010 (Pages 303- 307). Megan Isaac-Renton, BSc, Muhammad Morshed, PhD, SCCM Eleni Galanis, MD, MPH, FRCPC Sunny Mak, MSc Vicente Loyola, MD, FRCPC, Linda M.N. Hoang, MD, MHSc, FRCPC DISCLOSURES No relevant relationships by Munish Adhikari No relevant relationships by Ashma Ul Husna No relevant relationships by Yan Jiang No relevant relationships by Divya Kharel No relevant relationships by Gregory Polcha