Legionella Pneumonia on Point-of-care Ultrasound in the Emergency Department: A Case Report

INTRODUCTION: Legionella is an uncommon, atypical organism that can cause community-acquired pneumonia. Commonly associated with high fevers, gastrointestinal symptoms, and hyponatremia, it can be easily overlooked, especially during the coronavirus disease of 2019 (COVID-19) pandemic. Legionella has specific antibiotic treatment that will improve outcome; thus, its recognition is important. CASE REPORT: We present a case of Legionella pneumonia in a man presenting with shortness of breath and fever. The patient’s initial chest radiography was negative. With the use of point-of-care ultrasound (POCUS) the changes of atypical pneumonia could be seen. Ultimately Legionella was confirmed with urine antigen testing, and appropriate antibiotic treatment was started. DISCUSSION: Given the increased awareness of COVID-19 it is important to consider a broad differential with respiratory illness. Legionella pneumonia on POCUS is consistent with atypical pneumonia descriptions on ultrasound. Point-of-care ultrasound can be used to diagnose atypical pneumonia, specifically caused by Legionella in our case. CONCLUSION: Legionella is evident on POCUS but is difficult to distinguish from other infections with POCUS alone. One should consider Legionella if POCUS is positive for signs of atypical infection.