What is legionella bacteria?

After Legionella grows and multiplies in a building water system, water containing Legionella then has to spread in droplets small enough for people to breathe in. People can get Legionnaires’ disease or Pontiac fever when they breathe in small droplets of water in the air that contain the bacteria. read more

Legionnaires’ Disease Fact Sheet [1 page] This fact sheet describes what Legionnaires’ disease is, its symptoms, how it’s spread and treated, and who is at increased risk. read more

The genus Legionella is a pathogenic group of Gram-negative bacteria that includes the species L. pneumophila, causing legionellosis (all illnesses caused by Legionella) including a pneumonia-type illness called Legionnaires' disease and a mild flu-like illness called Pontiac fever. read more