Legionella.

Since the identification of Legionella two decades ago, a vast amount of information has accumulated concerning the microbiology, clinical manifestations, and therapy of infections due to these organisms. There are now more than 40 species of Legionella identified. The spectrum of legionellosis ranges from asymptomatic infection to serious pneumonia. Two clinical syndromes have been identified: Legionnaire's disease and Pontiac fever. Recent information suggests that the newer macrolides and newer fluoroquinolones are preferred therapy for serious disease.