Toronto Public Health Investigates 9 Legionnaires Disease Cases

Toronto Public Health is investigating legionnaires disease after nine cases were identified in late March and early April. The agency said the cases are believed to be linked because they all occurred close together in time and location.

The outbreak is concentrated in the southeastern area of Toronto. Public health officials said they have inspected the area for potential exposures and collected samples from possible sources in proximity to the cases.

Toronto Public Health in southeast Toronto

Toronto Public Health also said it has worked with other City divisions, local public health units, and provincial and federal partners. The agency said 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. 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, and the disease cannot be spread from human to human.

Ontario Legionnaires disease cases

Public Health Ontario said cases usually peak in the summer. Ontario reported 354 cases of Legionnaires’ disease between Jan. 1 and Dec. 3 last year, and 26 people died from the disease over that period.

For people in the affected part of Toronto, the practical step is to watch for symptoms including fever, cough, shortness of breath, and muscle aches, especially older adults, smokers and those with underlying health conditions. Toronto Public Health’s inspection and sampling work is aimed at narrowing the source, and the investigation now turns on what those samples show.