Victoria Health locate likely source of deadly legionnaires outbreak

There has been a major breakthrough in the investigation of a deadly disease outbreak that has claimed the lives of two Australians.

A deadly disease outbreak that has claimed the lives of two Australians could be nearing its end, with authorities confident they have located the source of the dramatic health scare.

Victorian Chief Health Officer Dr Clare Looker, speaking at a press conference on Monday afternoon, said the likely source of the legionnaires outbreak that has hit metropolitan Melbourne since early July had been located, with a cooling tower in the Laverton North suburb returning a positive result for legionella bacteria.

“I can confirm one of the towers we tested and which was subsequently disinfected earlier in our investigation has returned a positive legionella sample,” she said.

Victoria's chief health officer Dr Clare Looker said investigators had likely identified the source of the outbreak. Picture: NewsWire / Nadir Kinani

“This gives us increasing confidence that we have identified and already treated the source of this outbreak.”

Legionnaires’ disease is spread by breathing in fine droplets of water that contain legionella bacteria.

It can cause a chest infection with symptoms of fever, chills, cough, headache and muscle aches and pains, Dr Looker said in an earlier update.

Other atypical symptoms can include nausea, vomiting, diarrhoea and confusion.

Large-scale airconditioning systems can spread the disease.

It is not commonly spread from person-to-person or by drinking contaminated water.

Some 75 people have been hospitalised with legionnaires from mid July, Dr Looker confirmed.

A man in his 60s and a woman in her 90s died after contracting the illness.

Dr Looker, who received the positive result on Sunday night, expressed confidence the outbreak could be overcome.

“I’m reassured obviously that we’ve seen the case numbers come down following the intense program we’ve had of disinfection over the last week,” she said.

“It’s uncommon that you would see more than one tower affected at the same time. We’re visiting this site but we are also continuing with our other visits so until we have all our test results back and everything lined up … we’re still pursuing all options.”

Dr Looker said most of those who had contracted the illness were believed to have been exposed to the bacteria between July 5 and July 20 and began showing symptoms on or after July 15.

Authorities have tested 54 cooling towers at industrial and commercial sites across Melbourne, including shopping centres and factories.

The cooling tower that returned a positive result has been disinfected, she added.