legionella
What is it Legionella?
Legionella pneumophila is a rod-shaped bacterium that is naturally occurring. Infection by Legionella bacteria causes Legionnaires’ Disease which is a potentially fatal form of pneumonia. Legionella bacteria can be found in water sources such as rivers, lakes and reservoirs, soils, composts and other aquatic environments. They can also be found in purpose built water systems such as domestic hot and cold water systems, spa pools, storage tanks, evaporative condensers, humidifiers, pipes, garden hose, sprinklers, taps and showers.
At low temperatures (under 20ºC) the bacteria can survive but do not multiply as they are rendered dormant. They thrive mostly between 20ºC to 45ºC. Temperatures of 50ºC+ will start to kill Legionella bacteria with temperatures of 60ºC+ having over a 90% kill rate.
How do people get it?
Legionella bacteria can only infect your body through inhalation of contaminated water droplets or spray-mist often referred to as an aerosol. It cannot be contracted by drinking water or be passed from person to person.
Some people are at higher risk including:
• People over 45 years of age
• Smokers and/or heavy drinkers
• The elderly
• People suffering from chronic respiratory or kidney disease, diabetes, lung and heart disease
• Anyone with an impaired immune system
What increases the risk of Legionella?
• If the water temperature in all or some parts of the system is between 20°C - 45°C, which is suitable for growth
• If water is stored and/or re-circulated
• If there are deposits that can support bacterial growth providing a source of nutrients for the organism, e.g.
rust, sludge, limescale, organic matter and biofilms
• Outlets are infrequently used
• The system contains dead ends or unused pipe work
Symptoms
• A cough
• Shortness of breath
• A high temperature
• Flu-like symptoms
• Chest pain or discomfort - particularly when breathing or coughing
For further information visit
https://www.nhs.uk/conditions/legionnaires-disease/
Contact NHS on 111 if you are concerned about your health.
How to reduce the risk of Legionella?
The risk of Legionella causing illness in small domestic properties is generally low. Possibly the biggest risk is when you have been away from the property for more than a week or so, e.g. on holiday, or there are additional taps/showers/toilets that are not used daily. Good practice in this situation is to:
• Run the hot water taps for a minimum of 60 seconds
• Flush shower heads for a minimum of 60 seconds (to do this, remove from holder before turning on the shower, then hold down over plug hole to lessen risk of inhaling sprayed droplets)
• Shower heads should be dismantled and cleaned of scale and debris every 3 – 6 months
• Keep the hot water on your boiler system at a temperature of minimum 50°C - 60°C.
• Flush the toilet twice to circulate fresh water through the system and empty the cistern
The risk is lowered in instantaneous water heaters, such as combi-boliers and electric showers, as there is no water storage.
If unsure, seek advice prior to using any water systems.