NSW Health has confirmed that there have been cases of Legionnaires' disease detected in the Sydney CBD area, with five people confirmed to be identified with the bacteria that causes the illness as of May 26, 2022.

Health authorities have advised everyone in Sydney to stay vigilant and to keep a lookout for symptoms of the illness as it is often associated with contaminated cooling towers of large buildings. Don't worry, Sonder is here to help you understand what the disease is, what to look out for, and how to stay safe.


What is Legionnaires' disease?

Legionnaires' disease is an infection of the lungs (pneumonia) caused by the Legionella bacteria. While there are many different species of Legionella bacteria, the two that most commonly cause disease in NSW are:

  • Legionella pneumophila - These bacteria can contaminate air conditioning cooling towers, whirlpool spas, shower heads and other bodies of water.

  • Legionella longbeachae - These bacteria can contaminate soil or potting mix.

The illness is caused by breathing in the bacteria, which is commonly found in the environment, and is a risk for people who:

  • Are older (usually over 65)

  • Smoke

  • Drink heavily

  • Have chronic lung disease

  • Have underlying medical conditions such as diabetes, cancer or kidney failure.

Contrary to what the name suggests, the disease has nothing to do with trained soldiers in the French Foreign Legion or soldiers of the Ancient Roman army.

Where is it found?

The bacteria is commonly found in natural water bodies such as rivers, lakes, creeks and hot springs. For those living in cities, the bacteria can also also found in spas, potting mix, warm water systems and artificial systems that use water for cooling, and heating or industrial processes such as cooling towers.

What are the symptoms?

The early symptoms are similar to the flu and can include:

  • Headache (often severe)

  • Fever

  • Chills

Other symptoms may develop within a few days and sometimes other systems in the body are affected. This can cause:

  • Muscle aches and pains

  • A dry cough and shortness of breath.

  • Diarrhoea

  • Mental confusion

  • Kidney failure.

If you have these symptoms, see your doctor.

How do people get it?

A person can catch Legionnaires' disease by breathing in fine water droplets containing the bacteria. Note that the illness isn't a spreader risk as you cannot catch it from another person or by drinking contaminated water.

Legionnaires' disease is diagnosed through the use of special blood and urine tests as it can be difficult to distinguish from other types of pneumonia due to the similar symptoms.

Is there treatment?

Yes there is! Legionnaires' disease can be cured with antibiotics though there is no vaccine to prevent the disease. For more serious infections, treatment at a hospital may be required.

How do I protect myself?

The risk of Legionnaires' disease can be minimised through thorough and controlled cleaning of systems that may promote the growth of the Legionella bacteria, such as spas, hot water systems and cooling towers.

As the illness has been linked to potting mix, compost, and soil in recent years, make sure you always wear a mask and gloves when handling this material. Wet potting mix to reduce the dust and always thoroughly wash your hands afterwards using soap.

Related reading:


If you have any questions or need extra support, we're here to help you anytime in any language. Simply start a chat with us via the home screen of the Sonder app.

Information sourced from: NSW Health, Better Health, and Health Direct.

Image credit: Fallout: New Vegas

All content is created and published for informational purposes only. It is not intended to be a substitute for professional advice. Always seek the guidance of a qualified health professional.

Did this answer your question?