Legionnaires’ Disease FAQ

Below are answers to common questions about Legionnaires’ Disease based on information from the Centers for Disease Control (CDC).

What is Legionnaires’ Disease?

Legionnaires’ disease is a pneumonia caused by Legionella bacteria.

How is Legionnaires pronounced?

Legionnaires is pronounced LEE-juh-nares.

How is Legionella pronounced?

Legionella is prounounced LEE-juh-nell-a.

Why is it called Legionnaires’ Disease?

The name comes from an outbreak of the disease at an American Legion convention in which many people got sick with pneumonia.

Is Legionnaires’ Disease dangerous?

It is estimated that one in 10 people who gets sick from Legionnaires’ disease will die (source: Dooling KL, Toews KA, Hicks LA, et al. Active Bacterial Core surveillance for legionellosis–United States, 2011–2013).

Do many people get Legionnaires’ Disease?

U.S. health departments reported nearly 10,000 cases of Legionnaires’ disease in 2018. Legionnaires’ disease is likely underdiagnosed. Some estimates are as high as 100,000 cases per year.

Can I catch Legionnaires’ Disease from other people?

In general, people do not spread Legionnaires’ disease to other people but it may be possible in rare cases.

How do people get Legionnaires’ disease?

People can get Legionnaires’ disease by breathing in small droplets of water or mist in the air that contain Legionella.

Legionella occurs in nature in areas such as lakes or streams. It becomes a possible health issue when it grows and spreads throughout facility water systems such as:

  • Grocery store misters
  • Air conditioners
  • Plumbing systems
  • Hot water tanks
  • Water softeners
  • Fountains
  • Hot tubs or spas
  • Cooling towers

How do you prevent Legionnaires’ Disease?

The CDC states that the key to preventing Legionnaires’ disease is to make sure that building owners and managers properly maintain the water systems in their buildings. This will help to reduce the risk of Legionella growth and spread. A “Water Management Program” is an important component of this maintenance.

What is a Water Management Program?

A water management program identifies hazardous conditions in a facility and takes steps to minimize the growth and transmission of Legionella in the water systems. Developing and maintaining a water management program is a multi-step process that requires continuous review. Water Management Programs are an industry standard for large U.S buildings.

Is heat and flush an effective treatment for Legionella or the prevention of Legionnaires?

The use of heat and flush as a Legionella control treatment has historically been considered as a mitigation measure for Legionella. More recent analysis indicates that heat and flush or superheating should not be used because there are more effective control methods for Legionella.

Is hyperchlorination an effective treatment for Legionella or the prevention of Legionnaires Disease?

The use of hyperchlorination as a Legionella control treatment can provide some short term benefits. However, there may be a need for more effective control methods for Legionella if the hyperchlorination fails, and particularly in the long term.

Do you have questions about Legionnaires’ Disease or Legionella control in your facility? Contact Legionella Control Systems.

Contact Legionella Control Systems for CDC Legionella risk assessment and Legionella testing.