Temperature affects the survival of Legionellae as follows:
70 to 80 °C (158 to 176 °F) - Disinfection range
At 66 °C (151 °F) - Legionellae die within 2 minutes
At 60 °C (140 °F) - Legionellae die within 32 minutes
At 55 °C (131 °F) - Legionellae die within 5 to 6 hours
50 to 55 °C (122 to 131 °F) - They can survive but do not multiply
20 to 50 °C (68 to 122 °F)- Legionellae growth range
35 to 46 °C (95 to 115 °F) - Ideal growth range
Below 20 °C (68 °F) - Legionellae can survive but are dormant
Legionella is a waterborne bacterium that can cause diseases in humans. Legionnaires' disease is a characteristic pneumonia caused by the bacterium Legionella. It can be found naturally in lakes, streams and even in moist soil also in man made environments like in both domestic hot and cold water services. Legionella bacteria require nutrients to enable them to multiply. These nutrients are found in the water systems and include other common water organisms, sludge, scale and sediment but also iron often provided by corrosion particles.
Who is at most risk?
Elderly people (50+).
People with bad lungs - like smokers.
People with weakened immune systems.
Males are also three times more susceptible than females.
Healthy people can also be infected but as with most diseases the weaker you are the more susceptible you are.
How is it contracted?
As we have discussed Legionella is found on bodies of water but it is contracted by inhaling water spray (fine water droplets/aerosols) containing the bacterium. For example from showers, jet baths like whirlpool, taps, jacuzzis, and fountains.