NSW Health is investigating the possible contamination source after three people have now been confirmed with Legionnaires’ disease after spending time in Castle Hill.

All three cases developed the type of Legionnaires’ disease caused by Legionella pneumophila bacteria, a bacterial infection of the lungs, which can develop after a person breathes in contaminated water droplets. Legionnaires’ disease cannot be spread person to person.

The Hills Shire Council and public health units have commenced precautionary inspections of cooling towers in Castle Hill, as outbreaks can be associated with contaminated air conditioning systems in large buildings.

Three men who have been diagnosed have each spent time in the Castle Hill area during the period they contracted the infection. All patients reported becoming unwell between 3 and 5 February.

Dr Vicky Sheppeard, NSW Health’s Director Communicable Diseases, said Legionnaires’ disease causes fever, chills, a cough and shortness of breath.

“The time from exposure to the onset of symptoms is typically between two and 10 days, so people who were exposed could have symptoms already or develop them over the next week,” Dr Sheppeard said.

“The bacteria that cause Legionnaires’ disease live in water and can multiply in the water used to cool air conditioning systems, so infection is prevented by routinely maintaining and treating these systems.

“People outside can be exposed to the bacteria when a water cooling system emits contaminated water particles into the air.

“People who develop this disease are diagnosed by chest X-ray and a urine test, and usually require antibiotic treatment in hospital,” Dr Sheppeard said.

In 2016 and 2017 there were 93 and 81 cases of Legionella pneumophila infection notified to NSW Health.

For further information visit Legionnaires' disease.