Legionella outbreak in Melbourne

The Victorian Department of Health and Human Services (DHHS) has identified four confirmed cases of Legionnaires’ disease involving individuals who have spent time in the Brunswick area in Melbourne, including Sydney Road. All cases have required treatment in hospital. All had symptoms commencing in February and March 2020.

Particularly because of the current focus on COVID-19, health professionals have been alerted to consider Legionnaires’ disease as an alternative diagnosis for patients who have been around the Brunswick area since February 2020. This applies to patients who have influenza-like symptoms, particularly those with severe pneumonia.

The DHHS is continuing to investigate notified cases of Legionella infection to identify the possible source of their illness. Identified cooling towers in Brunswick have already been sampled and disinfected. Further investigations will continue.

As the DHHS notes, during the normal operation of a cooling tower, aerosols are formed and then carried into the environment through the tower exhaust. Legionella may be spread via the aerosols.

Cooling towers are ideal environments for Legionella because of stagnant water, nutrient growth, poor water quality and deficiencies of cooling tower systems.

Poorly located cooling towers also increase the risk to public health.

On December 14, 2019, the Public Health and Wellbeing Regulations 2019 replaced the Public Health and Wellbeing Regulations 2009. This included changes that relate to cooling tower systems and Legionella risks in certain premises – more details are available here.

The Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH), has highlighted a number of design application (DA) manuals and other technical resources that address cooling tower maintenance and prevention of Legionella. These include:

Leave a Reply

Your email address will not be published.