TRANSCRIPT:
The Sydney CBD has been full of revellers in the past week or so, celebrating Christmas and the New Year.
Now, they're being warned to be on alert for Legionnaire's disease, after the hospitalisation of seven people with the disease.
New South Wales Health says three women and four men, ranging in age from their 20s to 70s, have tested positive for the Legionella bacteria, and are being treated for pneumonia.
Acting Public Health director in South Eastern Sydney, Professor Mark Ferson, says anyone who might have visited the area in the last few weeks should be monitoring for symptoms.
"The early symptoms tend to be fever and chills, aches and pains, a cough - and if it progresses, shortness of breath is a sign that it's turned into pneumonia. People can really go downhill from there. So it's important that people developing those symptoms go and see a doctor."
New South Wales Health is reviewing the maintenance records of cooling towers in the Sydney CBD to determine which need to be investigated further.
Microbe ecology expert Richard Bentham says water coolers that are poorly maintained can create a perfect environment for the bacteria to develop.
"A lot of them are associated with air conditioning, or with the cooling of things like phone exchanges and things like that in large buildings. They use recirculating water to cool down refrigerants that then cools down equipment within the building. As that water recirculates, it pulls in with it dirt and dust from the environment, but it also gets warmer. So the whole thing becomes a sort of a large Legionella incubator."
Professor Robert Booy is an infectious diseases expert at the University of Sydney.
He has told Channel Nine that potting mix is another potential source.
"It spreads most easily through the air from water, but potting mix is possible too, that was first described in New Zealand. And that too can cause a pneumonia or influenza-like illness. It's a series of bacteria called Legionella, and they're all related to each other, and they can all cause trouble. And most commonly it comes through air conditioning but it can come through potting mix as well."
Meanwhile, Professor Ferson says teams are working closely with the City of Sydney Council to inspect cooling towers in the Sydney CBD.
"We're still looking at a large area of the Central Business District at this stage. We haven't been able to narrow it down. We have our environmental health officers from the public health units and from City of Sydney Council out there looking at cooling towers, trying to work out which ones may have caused the problem. Checking whether they're clean and have been disinfected properly. Collecting samples from them, which will go off to the lab to see whether they've got Legionella in them."
New South Wales Health says there's no need for panic now the alert has been issued.
They say if symptoms develop, the best thing is to see your doctor at the earliest opportunity.
Professor Bentham says the disease is not contagious between people - but wearing a mask can help keep the illness at bay.
"For people who consider themselves a high risk, have any existing respiratory problems, if you're going to go out and you're going to be in the CBD, wear a mask. That will reduce your the risk of your exposure. And if you don't have to go out, don't. Stay home. It's fairly simple."
