Toronto Public Health investigating Legionnaires’ disease outbreak after 9 confirmed cases

A photo of Toronto Public Health's offices at Dundas and Victoria streets in downtown Toronto. (THE CANADIAN PRESS/Cole Burston)

Toronto Public Health says it is investigating an outbreak of Legionnaires’ disease following nine confirmed cases.

In a statement to CP24, TPH said the cases, which were identified in late March and early April, are believed to be linked as “they all occurred close together in time and location.”

The local public health agency noted the outbreak is concentrated in the southeastern area of the city.

TPH said no source has been identified.

“Public health officials have inspected the area for potential exposures, collected samples from possible sources in proximity to the cases, and collaborated with other City divisions, local public health units, and provincial and federal partners,” TPH said.

The agency maintains that the risk to the public remains low.

Legionnaires’ disease is a type of pneumonia caused by Legionella bacteria, which are naturally present in water sources.

TPH said the bacteria can be found in poorly maintained and man-made water systems such as cooling towers, hot tubs, sprinkler systems, humidifiers and decorative fountains.

People can become sick when they breathe in small droplets of water containing the bacteria, TPH said, noting that Legionnaires’ disease cannot be spread from human to human.

Symptoms include fever, cough, shortness of breath, and muscle aches. TPH noted that older adults, smokers and those with underlying health conditions are at high risk.

Last year, between Jan. 1 and Dec. 3, Ontario reported 354 cases of Legionnaires’ disease. Of those cases, 26 died.

Public Health Ontario indicated that cases usually peaked in the summer.