People who have flu-like symptoms have been told to seek urgent medical care.

There has been an outbreak of Legionnaires’ disease in Melbourne’s outer north prompting a major health warning from authorities.

An outbreak of Legionnaires’ disease in Melbourne’s outer north has prompted a major health warning from authorities.

Six people who have spent time in Craigieburn and the surrounding suburbs have contracted the lung infection and spent time in hospital as of March 18, 2026.

Health authorities are currently investigating the source of the outbreak and testing cooling towers in the area.

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People who have been in Craigieburn or the suburbs of Mickleham, Greenvale and Roxburgh Park from late February and who have flu-like symptoms should seek urgent medical care, Victoria’s health department said.

Legionnaires’ disease is contracted by exposure to Legionella bacteria and outbreaks can occur when bacteria from environmental sources such as cooling towers on top of large buildings become contaminated.

The disease spreads by breathing in droplets of water that contain the bacteria, not from person to person.

Symptoms of Legionnaires’ include fever, chills, shortness of breath and a cough. It can lead to severe pneumonia.

“Other symptoms may include confusion and diarrhoea,” the health department said.

“Some people with Legionnaires’ disease may also develop kidney impairment.”

More information can be found on the health department’s website.