Legionella Pneumonia: When to Suspect, Diagnostic Considerations, and Treatment Strategies for Hospital-Based Clinicians

Abstract

Legionella species are fastidious gram-negative bacteria, ubiquitous in nature and associated with two distinct clinical syndromes: Legionnaire’s disease and Pontiac fever. Legionnaires’ disease is a severe multisystem disease comprised of fevers, rigors, headache, myalgias, dyspnea, delirium, and diarrhea, whereas Pontiac fever is a self-limited influenza-like illness. Either syndrome can occur during outbreaks, but typically only Legionnaires’ disease and pneumonia come to the attention of the emergency room physician or hospitalist. Here we describe an illustrative case of a 70-year-old female with COPD who presented to our hospital with severe Legionnaires’ disease. This article reviews the epidemiology and clinical manifestations of Legionnaires’ disease and updates the latest information on diagnostic approaches and treatment strategies for hospital-based clinicians and emergency department physicians alike.