Legionnaires’ disease spreads through Melbourne with source of outbreak still unknown

The outbreak of a dangerous disease is quickly spreading, with more people admitted to intensive care, as health authorities continue to search for the source.

Cases of Legionnaires’ disease are continuing to rise in Melbourne, with the “significant increase” causing multiple people to be hospitalised.

As of Thursday evening, health authorities have confirmed 60 cases in the state, after 40 were confirmed on Wednesday evening.

There are a further 10 suspected cases across metropolitan Melbourne and surrounding areas, with the outbreak spreading in the past week.

Most cases have required hospitalisation and people have been admitted to intensive care for severe pneumonia.

Authorities are still searching for the cause of the outbreak that is mostly affecting adults aged over 40 and are testing local cooling towers and any other potential sources.

The legionnaires’ disease outbreak is predominantly impacting people aged over 40. Picture: NewsWire / John Appleyard

Victorian chief health officer Clare Looker said sources across the city are being tested, but she believes the origin could be a single cooling tower.

“These numbers that we’re seeing at the moment are much greater than the usual three to six that we see a week so we think most cases are from a single source,” she said.

A total of 18 cooling towers in public places, factories and industrial sites have been disinfected, but the source is still not yet known.

Legionnaires’ disease can cause chest infections and prompt symptoms such as a fever, chills, cough, headache and muscle aches and pains.

Other less common symptoms may include nausea, vomiting, diarrhoea and confusion.

Those who are aged over 40, suffer from other medical conditions, are immune compromised or who smoke are most at risk.

Health authorities have detected 40 cases since last week. Picture: NewsWire / David Geraghty

Anyone who has visited metropolitan Melbourne or surrounding areas and develops symptoms should seek urgent medical attention.

On Tuesday, Dr Looker said she expected case numbers to “head north”.

Legionnaires’ disease is commonly found in natural bodies of water, including rivers, lakes, creeks and hot springs but can also be found in spas, warm water systems and artificial systems that use water for cooling, heating or industrial processes such as cooling towers

It is spread by breathing in fine droplets of water that contain legionella bacteria.

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