Legionnaires'

Online Q&A
December 2016

What is Legionnaires’ disease?

Legionnaires' disease is caused by exposure to a bacterium that is found in water and soil. It ranges in severity from a mild influenza-like illness to a serious and sometimes fatal form of pneumonia.

Symptoms include fever, headache, lethargy, muscle pain, diarrhoea and sometimes coughing up blood.

The disease can be treated with antibiotics.

Who is most at risk?

Most people exposed to the legionella bacterium do not get sick and the disease does not spread directly between humans.

Most people who do get sick are aged over 50 years. People with weak immune systems, chronic illnesses, smokers and those with a history of heavy drinking are at highest risk.

Outbreaks are often linked to poorly maintained air conditioning and water systems, humidifiers and whirlpool spas.

Where does the disease occur?

Legionnaires’ disease occurs worldwide but the rate of occurrence is unknown as many countries lack good surveillance systems to diagnose and detect the disease.

In Australia, Europe and the United States of America, there are about 10-15 cases detected per million population.

How can it be prevented?

The public health threat of Legionnaires’ disease can be reduced by regular maintenance, cleaning and disinfection of water and air conditioning systems to minimize the growth of the legionella bacterium.

There is no vaccine currently available for Legionnaire’s disease.

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