Auckland Regional Public Health Service
Ratonga Hauora-ā-Iwi ō Tāmaki Makaurau
Legionellosis or Legionnaires’ disease is caused by Legionella bacteria that live in the environment, especially in soil, composts, potting mixes and water.
People can get Legionella after inhaling mist or spray from water containing Legionella bacteria, or from inhaling dust from soil containing the bacteria.
It cannot be spread from person to person.
To reduce the risk of getting legionellosis:
If you are concerned about legionellosis or Legionnaires’ disease, call Healthline on 0800 611 116 or see your doctor or practice nurse.
There are many types of Legionella bacteria. They can be found in any type of water, and in soil. They have been found in roof water tanks, drinking water pipes, spa pools and all different types of soil, potting mixes and composts. Legionella are particularly common in warm stagnant water.
People can get Legionnaires’ disease after breathing in mists or spray (aerosols) from a water source that contains Legionella bacteria, or after inhaling dust from soil or compost. You cannot get it by drinking contaminated water, and it cannot be passed from one person to another.
Legionnaires’ disease symptoms include fever, chills, dry cough, muscle aches and pains, headache, diarrhoea and extreme tiredness.
It usually takes two to 10 days after exposure to the bacteria for symptoms to develop.
If you think you have Legionnaires’ disease, see your doctor. You will usually need to have a sputum (mucus/phlegm) test to confirm if you have the disease, and you may need a chest X-ray.
Legionnaires’ disease needs treatment with antibiotics, and most cases can be treated successfully. Healthy people usually get better after being sick with the disease, but they often need hospital care.
You can return to work when you feel better. There is no risk of infecting others.
To reduce the risk of Legionnaires’ disease from water, maintain the temperature of your household hot water cylinder at a minimum of 60°C. To ensure that water is delivered from the tap at a safe temperature, mixing valves – usually put underneath your sink – are highly recommended, and are required in new buildings. Mixing valves are the best way to ensure a safe water temperature at the tap, and can be fitted to older houses.
Do the following to reduce the risk of Legionnaires’ disease from soil, compost and seed and potting mixes.
Legionnaires’ disease is a notifiable disease. This means that health professionals or laboratories will inform us when someone has it. This allows us to look for sources, monitor the number of people who have the disease and give advice on how it can be prevented.
There are specific requirements for notifiable diseases in the Auckland region.
Last updated 22.11.2022