Aberdeen Hospital cooling tower being tested for legionella

The cooling towers at New Glasgow's Aberdeen Hospital have been shut off as a precaution, pending test results for legionella.

As of Thursday, there have been nine confirmed and 20 possible cases of the bacteria in the New Glasgow, N.S., area. It was confirmed last week at a nursing home and in other parts of the community.

In a news release on Thursday, Nova Scotia Health said Public Health identified the cooling towers as a spot where the bacteria could be growing. Lab testing to confirm the source can take several days to weeks, the health authority noted.

The cooling tower works by removing heat from water and transferring a small amount of evaporated water to the air. Nova Scotia Health said it's a key part of the hospital's air conditioning system.

In an email to CBC News, Nova Scotia Health said there has been no change to the hospital's air conditioning system.

It said the main and primarily cooling towers are operating, while a smaller third tower is shut down. Even with the shutdown of a third tower, the hospital can manage cooling with the primary towers, the health authority said.

How legionella spreads

The third tower is expected to be back in service within two weeks.

Legionella cannot be spread from person to person, the health authority said. It said the source for most infections is breathing the mist or vapour from a contaminated water source, like evaporated cooling systems, hot tubs and decorative water features.

The bacteria is also in soil and freshwater environments and grows in specific warm temperature ranges, Nova Scotia Health said.

A spokesperson for the health authority says that to remove the legionella, chlorination and additional cleaning and testing of the cooling tower is happening.

The health authority says there's a low risk for receiving care, visiting the hospital or working there. People can still come to the hospital if they need to.

Signs of legionella

The health authority says legionella rarely causes severe illness, but that risks for people increase with age, who smoke or have a chronic health condition. It can be treated with antibiotics if caught early.

Signs for legionella include:

• Fever.
• Chills.
• Dry cough.
• Muscle aches.
• Headache.
• Loss of appetite.
• Diarrhea.

Symptoms can appear two to 14 days after exposure, Nova Scotia Health said.

Citing privacy and confidentiality requirements, the health authority would not confirm whether anyone has died from the recent cases.

"It is also important to note that testing is not always definitive. In some cases we will know if legionella is the cause of illness for someone with similar symptoms," a spokesperson for Nova Scotia Health said in an email.