Legionnaires’ disease

Legionnaires’ disease is a type of pneumonia (lung infection) caused by Legionella bacteria, which are widespread in our environment. 

Legionella is found in natural water bodies such as rivers, lakes, creeks and hot springs. The bacteria are also found in spas, potting mix, warm water systems and artificial systems that use water for cooling, heating or industrial processes, such as cooling towers. 

A person may catch Legionnaires’ disease by breathing in fine droplets of water that contain the bacteria. Legionnaires’ disease is not contagious and cannot be spread from person to person or by drinking contaminated water. 

Who is at risk?

Although Legionella is common in the environment, not everyone who breathes in the bacteria will become unwell. People at greater risk of getting Legionnaires’ disease include those who:

• are aged over 40 years
• are smokers 
• drink heavily 
• have a chronic lung disease like emphysema 
• have a weakened immune system 
• have underlying medical conditions such as chronic heart, liver or kidney disease, diabetes, cancer or diabetes.

Symptoms of Legionnaires’ disease

Although Legionella is common in the environment, not everyone who breathes in the bacteria will become unwell. People at greater risk of getting Legionnaires’ disease include those who: 

• cough 
• shortness of breath 
• fever 
• headache 
• chills 
• muscles aches and pains.

Other atypical symptoms may include:

• confusion
• nausea 
• vomiting 
• diarrhoea. 

Diagnosis and treatment for Legionnaires’ disease

Special tests, requested by a doctor, are needed to diagnose Legionnaires’ disease. These may include: 

• a urine test – an easy test with the fastest result, results take between a few hours to 1-2 business days
• tests on sputum (mucus that is coughed up) or other samples from the airways / lungs
• blood tests taken during the illness after recovery.

The infection can be treated with commonly available antibiotics. There is no vaccine to prevent the disease. 

What to do if you develop symptoms of Legionnaires’ disease

Legionnaires’ disease can lead to serious illness and may require hospitalisation. If you develop symptoms of Legionnaires’ disease, you should seek urgent medical care through your GP or local healthcare provider.