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Legionnaires’ (LEE-juh-nares) disease is caused by a type of bacterium called Legionella (LEE-juh-nell-a). The bacterium is named after a 1976 outbreak, during which some people who went to a Philadelphia convention of the American Legion suffered from a new type of pneumonia (lung infection) that became known as Legionnaires’ disease. A milder infection, also caused by Legionella, is called Pontiac fever. The term “legionellosis” (LEE-juh-nuh-low-sis) may be used to refer to either Legionnaires’ disease or Pontiac fever.

Toolkit to Develop a Legionella Water Management Program

cover of Toolkit to Develop a Legionella Water Management Program

Get practical guidance on how to implement industry standards by identifying areas or devices in buildings where Legionella might grow or spread to people so that risk can be reduced through effective water management.


New Water Management Program Resources

Own or manage a building that may need a water management program? Find out what you need to know about

Healthcare facilities face unique challenges. Learn more about water management programs in healthcare facilities.

Environmental Investigation Videos

clinicians taking water samples

CDC has developed six instructional videos on various environmental aspects of legionellosis outbreak investigations.


ELITE Program

CDC's ELITE Program

The Environmental Legionella Isolation Techniques Evaluation (ELITE) Program was created as a way for laboratories to test their Legionella isolation techniques against standardized samples.