Where does Legionellosis come from?
The bacteria responsible for infections such as Legionnaires’ disease occur naturally at low levels in mud, soil and surface water courses. It is when the bacteria enter man made water systems that they find the optimum conditions for growth. These conditions include:
Temperature range of 20-45oC
The presence of nutrients such as rust, sludge, bio-films and organic materials such as those found in old seals and gasket materials
Although the bacteria thrive in the 20-45oC range they have been found in water temperatures as low as 6oC. Below 20oC and the bacteria becomes dormant and they cannot survive in temperatures above 60oC.
The following systems have been associated with outbreaks of Legionellosis:
Air conditioning/heating and ventilation units
Industrial air scrubbers
Commercial and domestic hot and cold water systems
Ornamental water features
Coolant for engineering cutting equipment
Greenhouse watering, irrigation or misting systems