Melbourne Legionnaires’ outbreak reaches 100 cases, two deaths

Melbourne's Legionnaires’ outbreak has claimed the lives of two Australians. A 90-year-old woman and a man in his 60s have died in hospital in Melbourne’s west.

The Victorian Department of Health issued an update over the weekend confirming the number of cases has increased, as the outbreak continues to spread.

It is reported that most people affected are over 40 years old, with many requiring hospitalisation, and those with severe community acquired pneumonia needing intensive care.

“Legionnaires’ disease can cause a chest infection with symptoms of fever, chills, cough, headache and muscle aches and pains. Other atypical symptoms may include nausea, vomiting, diarrhoea and confusion,” the health department said in a statement.

“All cases have visited or reside in metropolitan Melbourne.

“Those most at risk are adults aged over 40 years, especially people with other medical conditions or immunocompromised, or who smoke.”

Test results of those who have the disease have indicated the Melbourne outbreak is caused by “Legionella pneumophilia serogroup 1” which can be detected through a unitary antigen test.

Victorian Chief Health Officer Dr Clare Looker told a press conference last week that the source of the outbreak 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.

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

“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.”

Authorities have tested hundreds of towers and disinfected 70 so far, with ongoing testing being performed.

The bacteria that causes the disease are widespread in the environment. They are found in natural bodies of water like rivers, lakes, creeks and hot springs. They 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.

A more common source of Legionnaires’ disease can be caused by bacteria usually found in contaminated air-conditioning systems in large buildings.

The bacteria is not commonly spread person-to-person or from drinking contaminated water.

The Department of Health is urging anyone who lives in, works in or has visited metropolitan Melbourne and surrounding areas to seek urgent medical care if they develop symptoms.