​​Legionella / Legionellosis / Legionnaire's Disease

What is Legionellosis (Legionnaire's Disease)?

Legionellosis, or legionnaire's disease, is a bacterial disease of the lungs caused by Legionella pneumophila. The disease can range from a mild respiratory illness to severe pneumonia and death. ​

How does it spread?

People get sick with Legionella by breathing in mist containing the germ. Typically, Legionella doesn't spread through person-to-person contact. Legionella is found in low counts in fresh water environments and rarely causes disease, but can pose a health risk if it gets in building water systems and grows there.

Who is at risk for getting sick with Legionella?

Most people don't get sick if exposed to Legionella, but some factors can increase the risk for it, such as:

• Being a current or former smoker
• Being 50 years or older
• Having chronic lung disease
• Having cancer
• Having a weakened immune system
• Having kidney or liver failure
• Having diabetes

Preventing Legionnaire's Disease

Reducing Legionella's risk for growth in water is key for preventing it.

At home: Regularly clean devices that use water (i.e., humidifiers, CPAP machines), flush faucets, showerheads and toilets that are not frequently used, and after water pressure drops.

In motor vehicles: Always use windshield cleaner fluid from known manufacturers. Never use water!

In buildings and public hot tubs: Building owners and managers should have a water management program to control Legionella.

Resources and Printables

KCHD: Resources for Water Management – Long-Term Care
KCHD: What is Legionnaire's Disease?
KCHD: Legionnaire's FAQ with QR Codes​​