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Legionnaires' Disease

11 Apr 2012
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Legionnaires' disease is a lung infection caused by legionella bacteria that can potentially be fatal.

It is contracted by breathing in small droplets of contaminated water. It cannot, however, be spread directly from person to person.

Legionella pneumophilia bacteria can be found in sources of water (lakes and rivers) and can turn up in artificial water supply systems such as air-conditioning units and cooling towers. Larger buildings with more complex water supply systems are more vulnerable to the spread of legionella bacteria. It can also occur in domestic water systems, being present in domestic shower heads, spa pools, water blasting water, and so on.

A second strain, legionella longbeachae, can be inhaled from dust or mist in contaminated compost, soil and potting mix.

  • Exposure to legionella contaminated water, compost, soil or potting mix


Risk factors for developing Legionnaire's disease can include:

  • Being a smoker
  • Having diabetes
  • Having kidney disease
  • Having a compromised immune system
  • Having a pre-existing lung condition
  • Having a heart condition
  • Having a liver condition
  • Being over the age of 50
  • Having cancer (in particular lung cancer or leukaemia)


  • Fever
  • Muscle pain
  • Chills
  • Fatigue
  • Change in mental state, confusion
  • Persistent cough
  • Chest pains
  • Shortness of breath
  • Loss of appetite


  • Hospital treatment
  • Antibiotics


Legionnaires' disease can be a serious illness, especially for the elderly and those with compromised immune systems or pre-existing health conditions. Most people, however, will recover with antibiotic treatment.

If you have the above symptoms go to your nearest emergency room immediately or dial 111 for an ambulance.




Video: Legionnaires' Disease: What You Need to Know




Department of Labour – Legionellosis



NHS – Legionnaires' Disease
Health and Safety Executive – Legionnaires' Disease
BBC Health – Legionnaires' Disease
Health Protection Agency UK – Legionnaires' Disease
MedlinePlus – Legionnaires' Disease



British Medical Journal
Journal of the American Medical Association
The Lancet


FORUMS – Legionnaires' Disease Forum



The information above is of a general nature and is designed to provide you with an overview of the topic, with links to local and international resources that may be of interest. We do our best to ensure that this information is accurate and up to date.

You should always, however, seek specific professional medical advice, treatment and care appropriate to you, and as such we strongly recommend you consult with your general practitioner first.



Updated April 2012
Image source: Wikimedia Commons – Legionella