According to the CDC, as many as 18,000 Americans are hospitalized each year after contracting Legionnaire’s Disease.  Caused by the bacteria Legionella pneumophilia, the disease is spread by aerosols that are inhaled.  The disease was named following an outbreak in 1976 that killed 29 delegates to an American Legion conference in Philadelphia.

Legionella bacteria are ubiquitous in the environment, and are primarily found in water. The bacteria grow best in water temperatures between 68°F and 122° F.   These conditions are frequently present in:

-Cooling towers

-Large plumbing systems

-Hot water tanks

-Hot tubs

How do people get Legionnaires’ Disease?

Legionella bacteria grow in water reservoirs.  Bacteria become aerosolized as a mist or vapor and are inhaled into a person’s respiratory tract.   The disease is not contagious and therefore is not transmitted person-to-person.  There is no evidence that drinking water contaminated by Legionella will lead to contracting the disease.

VIGILAIR® and Legionnaires’ Disease

The Heating Ventilation and Air Conditioning (HVAC) systems of buildings provide a perfect environment for proliferation and dissemination of Legionella.  Many naturally occurring bacteria such as Legionella enter the HVAC system’s fresh air intake.  These airborne contaminants become part of the air stream being treated by the HVAC system.

During the cooling season, the HVAC system removes heat and moisture from the air before distributing it throughout the building’s occupied spaces.  A by-product of this process is water from the air that condenses on the cooling coil.  Condensed water drips down and collects in drain pans.  Over time, drain pans become clogged and create an excellent reservoir for Legionella growth.

In addition to providing a place for Legionella to grow, HVAC systems also present an efficient vehicle for spreading the aerosolized bacteria throughout a building.  VIGILAIR® technology uses germicidal UV to prevent Legionella and other bacteria from growing on cooling coils and drain pans.  For more information on VIGILAIR® and how you can protect your building and its occupants from Legionnaires’ Disease and other airborne contaminants, click here.