Legionnaires' disease is an infection of the lung caused by the Legionella bacteria. This bacteria causes a type of pneumonia which can be fatal. It usually takes 2 to 10 days for the symptoms to develop after inhaling the bacteria.
Legionella presents in two forms:
Legionella bacteria is found naturally in low levels in the environment. In the absence of effective treatment Legionella can breed to high numbers in water cooling systems (cooling towers), warm water systems or water heaters, shower heads, spa pools or potting mix.
The most common way Legionnaires’ disease is contracted is by breathing air contaminated with Legionella. Air is contaminated when aerosols containing Legionella are released. The aerosol needs to be very small so that it can penetrate deeply into the lung.
It is not transmitted from person to person.
Not all of the symptoms need to be present for diagnosis. People with these symptoms should see their doctor immediately.
Specialised laboratory tests are necessary to establish a definite diagnosis of Legionnaires’ disease.
Gram stains can be made from secretions from normally sterile sites such as lung tissue, pleural fluid, trans-tracheal aspirate, bronchial lavage, lung biopsy, or sputum from the lower respiratory tract.
Note: Legionnaires’ disease is a notifiable disease under the Public Health Act.
The proper installation, maintenance and cleaning of systems is a legal requirement under the Public Health Act and Microbial Control Regulation.
Building occupiers who fail to meet these requirements are liable to heavy fines or even imprisonment. Systems can be inspected at any time.
Location of air intakes should be carefully planned. They should be placed well away from exhaust discharges and cooling-towers to avoid cross-contamination. They should also be away from pedestrian areas.
All air intakes should be above the ground to make sure that dust, rain and small animals don’t get into them.
Ductwork should be graded to prevent water collection and should be thoroughly cleaned before the system begins operating.
Installation of the system must be reported to local government authorities so that a local register of systems can be kept up to date.
Local councils are required to keep a register of water-cooling and warm-water systems installed on premises in their area.
It is your responsibility to ensure that the Council is provided with the necessary information.
The Legionnaires’ Disease Emergency Management Plan prepared by the NSW Health Department will be put into action if an outbreak occurs. You may be required to submit a water sample to an Environmental Health Officer from the Department, or local council, or alternatively, such authorised officer may take a water sample for scientific analysis.
For more information regarding legionella control, visit the NSW Health Department.