10 cases of legionnaires’ disease in Montreal, two people have died: public health

Montreal public health officials are investigating after two people died of legionnaires’ disease in the eastern part of the city, a department spokesman said Wednesday.

The Public Health Department said 10 cases of the disease, which often causes pneumonia, have been identified since mid-June, all within a large area east of downtown Montreal.

Dr. David Kaiser, head of environmental and population health, said legionnaires’ disease is a respiratory infection that can be caught by breathing in small droplets of water suspended in the air that are contaminated with the legionella bacteria.

Public health is still working to identify the source of the infections and has examined water-cooling towers in the area. 

“It is likely that there are several sources,” Kaiser said. Aside from cooling towers, other frequent sources of contamination are splash pads, sewer maintenance work and hot water heaters.

Public health is asking residents to ensure their hot water heaters are kept at a temperature above 60 C to prevent growth of the bacteria.

Kaiser also sought to reassure the population, noting the disease is not transmitted from person to person. “For the population, the risk remains very low,” he said.

Each year, around 50 Montreal residents contract legionnaires’ disease.  

So far in 2021, the city has recorded 20 cases, which is normal for this time of year. But Kaiser said a higher number of cases than usual is concentrated in the city’s east end, where an infection identified in June was followed by several cases in July.

In 2012, an outbreak in Quebec City led to 181 infections and 14 deaths. It took nearly two months for officials to identify the source of that outbreak: a cooling tower atop an office building in Quebec City’s lower-town area.

This report by The Canadian Press was first published Aug. 4, 2021.

Stéphanie Marin, The Canadian Press