Legionnaires’ Disease

Legionnaires’ (LEE-juh-nares) disease is a type of pneumonia (lung infection) you get from breathing in Legionella bacteria. It can affect your lungs, brain and gut (gastrointestinal tract). Legionella also causes Pontiac fever, a less serious illness with flu-like symptoms. Legionnaires’ disease can be life-threatening.

What’s the difference between Legionnaires’ disease and pneumonia?

You get Legionnaires’ disease when Legionella infects your lungs. Most people with Legionnaires’ disease who are hospitalized have fever and cough but may also have other pulmonary symptoms such as diarrhea and confusion.

Who’s more likely to get Legionnaires’ disease?

Most people don’t get Legionnaires’ disease, even if they’ve been around Legionella bacteria. But some people are more likely to get sick with a Legionella infection than others. You have an increased risk of getting Legionnaires’ disease if you:

• Are older than 50.
• Smoke or used to smoke cigarettes.
• Have a weakened immune system. Certain medical conditions (like HIV, diabetes, cancer and kidney or liver disease) and medications can compromise your immune system.
• Have a long-term respiratory illness, such as chronic obstructive pulmonary disease (COPD) or emphysema.
• Live in a long-term care facility.
• Have stayed in a hospital recently.
• Have had surgery requiring anesthesia recently.
• Have received an organ transplant recently.

How common is Legionnaires’ disease?

Up to 18,000 people are hospitalized with Legionnaires’ disease each year in the U.S. It’s more common between June and October.