Victoria's health department is urging people to get tested after an outbreak of Legionnaires' disease in Melbourne's south-east.
Three people who spent time in Cheltenham or surrounding suburbs have tested positive for the infectious disease within the last month.
The department has advised anyone who was in the area from early May and has developed flu-like symptoms to seek urgent medical care.
Healthcare professionals have also been warned to watch out for people with the symptoms, particularly anybody with atypical or severe pneumonia.
Authorities are testing cooling towers — a common source of the disease — and other potential sources in the area in an effort to find out where the infections have come from.
Legionnaires' disease is caused by Legionella bacteria, which are widespread in the environment. They are found in natural bodies of water such as rivers, lakes, creeks and hot springs.
The bacteria are also found in spas, warm water systems and artificial systems that use water for cooling, heating or industrial processes, such as cooling towers, as well as potting mix.
Legionnaires' disease is spread by breathing in fine droplets of water that contain the bacteria. It is not spread from person-to-person or by drinking contaminated water.
Only a few people who come into contact with the bacteria go on to develop the disease, but those most at risk include the elderly, smokers, heavy drinkers, the immunocompromised and those suffering from pre-existing medical conditions such as diabetes and cancer.
Symptoms of Legionnaires' disease can include headaches, shortness of breath, chills, fever, muscle pain, a cough, confusion and diarrhoea.
Last year, a Sydney woman died of Legionnaires' disease after contracting it from potting mix, sparking a warning by NSW authorities to gardeners to always wear gloves and a mask while handling the product.
An outbreak in Melbourne in 2018 killed an elderly man and sparked calls for a review of auditing and regulation of cooling towers.
