About the Disease
Legionella bacteria can cause a serious type of pneumonia (lung infection) called Legionnaires’ disease. Legionella bacteria can also cause a less serious illness called Pontiac fever.
Causes, How it Spreads, and People at Increased Risk
Signs and Symptoms
Diagnosis, Treatment, and Complications
Prevention
History, Burden, and Trends

Legionnaires’ Disease Fact Sheet pdf icon[1 page]
This fact sheet describes what Legionnaires’ disease is, its symptoms, how it’s spread and treated, and who is at increased risk.
Page last reviewed: March 25, 2021