Legionnaires disease is a lung infection caused by Legionella pneumophila bacteria. These bacteria usually grow in places that hold warm water, such as:
Large air-conditioning systems.
Complex plumbing systems, such as pipes, faucets, and showerheads in hotels, hospitals, or cruise ships.
Public whirlpool spas.
Decorative fountains.
Hot water tanks.
The only way to get legionnaires disease is to breathe in mist containing the bacteria. The disease cannot be passed from person to person.
RISK FACTORS
This condition is more likely to develop in people who:
Are age 50 or older.
Smoke.
Drink a lot of alcohol often.
Have long-lasting lung problems.
Have a weak body defense