Legionnaires' disease

Legionnaires' disease

Legionnaires' disease is a lung infection you can catch by inhaling droplets of water from things like air conditioning or hot tubs. It's uncommon but can be very serious. It's caused by the bacterium Legionella pneumophila and related bacteria.

There are 200-250 reported cases in the United Kingdom each year.

How you get Legionnaires' disease

You can catch Legionnaires' disease if you breathe in tiny droplets of water containing bacteria that cause the infection. You can catch it from things like:

  • air conditioning systems
  • spa pools and hot tubs
  • showers, taps and toilets

Person-to-person spread of the disease has not been documented.

Initial symptoms of Legionnaires' disease include:

  • high fever
  • chills
  • headache
  • muscle pain

Legionnaires' disease can be treated effectively with antibiotics.

Exposure risk

There is risk of exposure to legionella bacteria in:

  • water systems incorporating a cooling tower
  • water systems incorporating an evaporative condenser
  • hot and cold water systems
  • other plant and systems containing water which is likely to exceed 20 degrees and which may release a spray or aerosol during operation or when being maintained

Legionaire's disease in the borough

There has not been an outbreak of the disease in borough since 1989.

We continually work to minimise any risk and have a documented procedure in place to deal with an outbreak. This would involve setting up an outbreak control team in co-operation with NHS Kensington and Chelsea and other experts.


If your premises has a cooling tower or evaporative condensers you have to notify the Council under Cooling Towers and Evaporative Condensers Regulations 1992. This includes premises where the enforcing authority is the Health and Safety Executive.

Read more about registering cooling towers.

Cooling tower inspections

We inspect local premises with a cooling tower or evaporative condenser once or twice a year. We also inspect supporting documents about:

  • water treatment
  • monitoring
  • cleaning

General inspections

During general inspections we assess the risk from legionella in hot and cold water systems and anything that can release a spray or aerosol such as:

  • humidifiers
  • spa baths
  • pools
  • car washes
  • indoor fountains and water features