SMDHU issues tips, guidance on Legionnaires’ disease

The health unit's public health inspectors conduct risk assessments to determine how often inspections are needed at food establishments. - Chris Simon/Metroland

The Simcoe-Muskoka region’s guiding health agency has some advice for municipalities and cooling-tower operators to prevent further outbreaks of a potentially deadly bacteria.

In a letter addressed to the chief administrative officers of County of Simcoe and District of Muskoka municipalities, which was included on the July 6 City of Barrie circulation list, Simcoe Muskoka District Health Unit medical officer of health Dr. Charles Gardner urged local governments to take action to stop the spread of Legionella pneumophila — which can lead to the lung infection commonly known as Legionnaires’ disease.

They can do this by circulating a health unit-issued letter that contains a list of “strong recommendations” to building operators within each municipality who may utilize the towers as part of their HVAC systems.

Cooling towers are often installed on HVAC systems for larger facilities such as apartment buildings, malls, schools, hospitals, arenas and factories. But the health unit has difficulty keeping track of cooling-tower locations, going so far as to ask the Ontario government in 2021 to implement a mandatory cooling-tower registry, since no record is maintained in building construction.

“Legionellosis can result in mild to severe respiratory illness,” Gardner said. “These respiratory infections occur through inhalation of aerosolized water droplets contaminated with Legionella bacteria. Cooling towers are a known significant contributor to Legionella exposures. Aerosolized bacteria can place those living and working in surrounding areas at risk. However, the risk of outbreaks can be minimized by regular maintenance, cleaning, disinfection and testing in accordance with best practices.”

Legionella bacteria is commonly found in natural freshwater environments. However, it can become a health concern in water systems such as cooling towers, plumbing in large buildings and certain medical devices when conditions allow the bacteria to multiply.

Residents can develop Legionnaires’ when they inhale aerosolized water droplets containing the bacteria. They cannot get the disease by drinking water or through contact with other people.

Most people exposed do not become ill. Those at heightened risk are typically over the age of 50, smokers or those with weakened immune systems, lung disease or other chronic health conditions.

Legionnaires’ is described by the Mayo Clinic as a “severe form of pneumonia.”

To reduce the spread, the health unit recommends tower operators undertake preventive maintenance, bacterial testing, monitoring and, when necessary, corrective action in accordance with established federal standards.

The health unit has dealt with multiple significant outbreaks of the disease in recent years, including two traced to Orillia's Rotary Place and a multi-case cluster caused by an unknown source in Barrie in 2020.

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Chris Simon is a veteran journalist with The Barrie Advance. Got a news tip? He can be reached on Facebook, [email protected] or 647-250-8902.