06/24/25 Public Health Education Topic: Legionella
- Health Department
- 1 day ago
- 1 min read
Per CDC
Key points
The key to preventing Legionnaires' disease is to control Legionella growth and spread.
Buildings and devices at increased risk for Legionella growth and spread should have a water management program based on industry standards.
Owners of certain devices, like hot tubs, should take steps to reduce Legionella risk.
Bacteria called Legionella cause Legionnaires' disease. Legionella is found naturally in freshwater environments and can become a health concern in human-made building water systems.
Owners of the following devices should follow the manufacturer's instructions regarding cleaning, disinfecting, and maintenance:
Cooling towers
Decorative fountains
Hot tubs
Centrally installed misters, atomizers, air washers, or humidifiers
CDC has developed a toolkit on how to control Legionella in common sources of exposure, including decorative fountains and hot tubs.
Where Legionella can grow or spread
Legionella can grow in many parts of building water systems. Examples include:
Expansion tanks
Faucet flow restrictors
Hoses, pipes, valves, and fittings
Hot and cold-water storage tanks
Water filters
Water hammer arrestors
Water heaters
Certain devices spread water droplets, which can have Legionella in them. Examples include:
Aerators
Centrally installed misters, atomizers, air washers, and humidifiers
Medical equipment
Nonstream aerosol-generating humidifiers
Point of use fixtures such as showers, sprayers, and faucets
Examples of medical equipment includes CPAP machines, hydrotherapy equipment, and bronchoscopes.
In other devices, Legionella can both grow and spread. Examples include:
Cooling towers
Decorative fountains
Electronic and manual faucets
Hot tubs
Ice machines
Infrequently used equipment including eyewash stations
To learn more visit: About Legionella Control | Controlling Legionella | CDC
