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Guidance on Legionnaires' disease

Legionellosis is a collective term for diseases caused by legionella bacteria including the most serious Legionnaires' disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever.

Legionnaires' disease is a potentially fatal form of pneumonia and everyone is susceptible to infection. This risk increases with age, but some people are at higher risk, including; people over 45, smokers and heavy drinkers, those suffering with chronic respiratory or kidney disease, diabetes, lung and heart disease, or anyone with an impaired immune system.

How do people get Legionnaires' disease?

It is contracted by inhaling small droplets of water, suspended in the air, containing the bacteria. Certain conditions increase the risk, if:

  • the water temperature in all or some parts of the system is between 20-45 °C, which is suitable for growth
  • water droplets are created and dispersed
  • water is stored and/or re-circulated
  • there are deposits that can support bacterial growth e.g. rust, sludge, scale and organic matter.

Water Safety

If you've been away from home and your taps haven't been used for over 7 days, we recommend the following tips to prevent the build-up of water born bacteria (legionella):

  1. Run all taps and showers for a minimum of 5 minutes then leave the room - ensure that you first remove the shower head and place the hose directly over the plug hole to prevent the production of water vapour.
  2. If your hot water system has been allowed to cool, the hot water cylinder should be heated up to its normal operating temperature. This usually takes between 1 and 2 hours.
  3. After the system has been adequately heated, turn the hot taps on and flush the hot water through the system for 5 minutes. 

Open windows where possible during this process.

Caution: To avoid injury, children should be kept away from any hot running water as the temperature can reach 60c.