Australian health officials are investigating four people infected with Legionnaires’ disease who all spent time in Sydney’s Central Business District (CBD).

Legionella/CDC
Legionella/CDC

City of Sydney and public health units have commenced inspections of cooling towers in the CBD, starting in the Town Hall area, as outbreaks can be associated with contaminated air conditioning systems in large buildings.

Four men who have been diagnosed have each spent time in the CBD during the period they contracted the infection, including the Druitt, Market, Sussex and Pitt Street areas. The men are currently being treated in hospitals.

NSW Health urges anyone who lives, visits or works in the Town Hall area and who develops symptoms of Legionnaires disease to visit their GP.

Legionnaires’ disease gained national notoriety in 1976 when the Centers for Disease Control and Prevention (CDC) discovered it during an epidemic of pneumonia among American legion members at a convention in Philadelphia.

The causative organism is the bacteria, Legionella pneumophila. Other species have also been implicated in Legionnaires’ disease. The legionella bacteria are found throughout nature, because of this most people become exposed to it but few develop symptoms.

The primary place in nature it’s found is water sources particularly at warmer temperatures; lakes, rivers and moist soil.

It is also found in man-made facilities (frequently the source of outbreaks) such as air-conditioning ducts and cooling towers, humidifiers, whirlpools and hospital equipment.

People get exposed through inhaling infectious aerosols from these water sources. There is no transmission from person to person.

The infection can appear in two clinical forms: Legionnaires’ disease and Pontiac fever.

Both conditions are typified by headache, fever, body aches and occasionally abdominal pain and diarrhea.

Legionnaires’ disease is the cause of pneumonia where a non-productive cough is typical. Fatality rates of this form of the infection are around 15 % even with improvements in treatment.

Pontiac fever is a self-limiting flu-like illness that does not progress to pneumonia or death. Diagnosis is usually made by typical symptoms in an outbreak setting.

Certain health conditions make you more susceptible to infection to include increasing age, smoking, chroniclung disease, malignancy and diabetes mellitus.

Legionnaires’ disease is treatable with antibiotics.

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