Outbreak of Legionnaires’ disease in Melbourne

The Victorian Department of Health is investigating an outbreak of Legionnaires’ disease with 22 confirmed and 6 suspected cases notified since 26 July across metropolitan Melbourne and surrounding areas.

Legionnaires’ disease is a lung infection caused by the Legionella bacteria. Infection occurs when contaminated dust or water droplets are inhaled, and it is not spread from person to person², with the time taken from exposure to onset of symptoms between two to 10 days³.

Those at risk of Legionnaires’ disease include people who are immunocompromised, have underlying medical conditions including chronic lung disease, diabetes and heart, liver or kidney disease, aged over 40, and smokers^1,4.

VIC Health is advising people who live in, work in, or have visited metropolitan Melbourne and surrounds and who have developed symptoms of Legionnaires’ disease, to seek urgent medical care.

Legionnaires’ disease usually presents as a chest infection with symptoms including fever, chills, cough, headaches and muscle aches and pains. Less typical symptoms may include confusion, nausea, vomiting and diarrhea. Legionnaires’ disease can lead to severe illness and may require hospitalisation.

Legionella bacteria are commonly found within the environment in water and soil, including building cooling towers, humidifiers and air conditioning systems, fountains, spas and showers². Exposure can occur in the home, workplace, or public settings including healthcare and shopping centres.

Prevention of Legionnaires’ disease is through cleaning and maintenance strategies to limit bacterial growth within water systems, cooling units and water sources, including regular inspection, disinfection and maintenance³.  Risk assessments during the planning phase of construction and renovation activities in healthcare settings, are a required strategy to minimise the risk of Legionnaires disease and ensure management plans are in place during construction activity. Refer to the ACIPC position statement IPC considerations for planning and construction in healthcare settings for more information on risk assessments – https://www.acipc.org.au/wp-content/uploads/2024/06/Position-Statement-Construction-and-Renovation-Position-Statement-Issued-18-06-24.pdf

1. Better Health Channel. Legionnaires’ disease. The Victorian Government. Accessed 30 July, 2024. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/legionnaires-disease
2. Health direct. Legionnaires’ disease. Healthdirect Australia Limited,. 2024. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/legionnaires-disease
3. NSW Health. Legionnaires’ disease fact sheet. NSW government. Updated 2 June 2022. Accessed 30 July, 2024. https://www.health.nsw.gov.au/Infectious/factsheets/Pages/legionnaires_disease.aspx
4. Victorian Department of Health. Outbreak of Legionnaires’ disease in metropolitan Melbourne. Victorian Government. Accessed 30 July, 2024. https://www.health.vic.gov.au/health-alerts/outbreak-of-legionnaires-disease-in-metropolitan-melbourne