Sources of Legionella
The spread of legionella bacteria typically occurs through water systems, with illness occurring after individuals have inhaled aerosols that have been contaminated with the Legionella bacterium.
Naturally occurring in water and soil, the Legionella bacterium is widely distributed in water systems and certain conditions tend to promote and propagate the growth of Legionella:
- Water ph levels between 5.0 and 8.5
- Sitting or stagnant water
- Temperatures between 20° and 50° C with optimal growth occurring between 35° and 46°C
- Micro-organisms including Pseudomonas, flavobacteria and algae, which supply essential nutrients for the growth of Legionella or harbor the organism
Aerosols that can be inhaled may come from a variety of water sources:
- Water distribution systems of large buildings (hotels, hospitals, ect.)
- Cooling Towers
- Showers
- Spas
- Commercial Ice Machines
- Body Misters
- Potting Soil
- CPAP Machines