The number of legionnaires' cases in Melbourne has almost doubled in two days as authorities continue to try and find the source of the outbreak.
Sixty patients are confirmed to be suffering from the disease as of Thursday, according to Victoria's Department of Health, and test results for 10 suspected cases are due soon.
The total is up from 33 on Tuesday and most of those diagnosed have been hospitalised, with some admitted to intensive care because of severe cases of pneumonia.
Health Minister Mary-Anne Thomas says the health system will cope with the growing cases.
"Our GP practices, all of our health services, are all alert to the symptoms of legionnaires' and are well placed to be able to treat people that receive the care," she told reporters at parliament on Thursday.
Ms Thomas said it was concerning the source of the disease had not been found but the health department was working to identify it.
Most of the patients are aged over 40 and all have visited or live in metropolitan Melbourne.
The health authority is testing potential sources across the city and 18 cooling towers at public venues, factories and industrial sites have been disinfected but the source has yet to be confirmed.
Legionnaires' disease is caused by the legionella bacteria, which is found in natural bodies of water as well as spas, warm water systems, potting mix and artificial systems that use water for cooling.
Symptoms usually include a chest infection, aches, headache, fever, cough and chills.
People with underlying diseases, particularly those who are immunocompromised, elderly people and smokers are at greater risk of infection.
"It's not an infectious disease," Ms Thomas said. "We need to locate the source and that's how we resolve the impact."
Victorians experiencing a chest infection should make sure they seek medical care, she said.
