infectious diseases
Legionella Infections
Introduction
Legionella pneumophilais a gram-negative bacillus that most often causes pneumonia with extrapulmonary features. Diagnosis requires specific growth media, serologic or urine antigen testing, or polymerase chain reaction analysis. Treatment is with macrolides, fluoroquinolones, ordoxycycline. Legionella pneumophilawas first recognized in 1976 after an outbreak at a convention of the American Legion in Philadelphia, Pennsylvania—thus, the name legionnaires’ disease. This disease is the pneumonic form of an infection usually caused byLegionella pneumophilaserogroup 1. Nonpneumonic infection is called Pontiac fever, which manifests as a febrile, viral-like illness. 