Legionellosis increasing in Ontario

Reports of Legionellosis have been increasing throughout Ontario. There have been 13 confirmed and 1 probable cases of legionellosis reported between July 1 and July 28, 2021 in the Region of Peel. Eleven of the cases are in the City of Mississauga and 3 cases are in the City of Brampton.

Legionellosis is an acute infection caused by the bacterium, Legionella pneumophila. It is acquired through inhalation of contaminated aerosols or mists from devices such as cooling towers, humidifiers, showers and decorative fountains. It is not spread from person to person. Patient risk factors for Legionellosis include: Increasing age (50 years or older), Smoking, Chronic obstructive pulmonary disease (COPD), Diabetes mellitus, Renal disease, Malignancy, Weakened immunity (e.g., transplant, or long-term corticosteroid use). Signs and symptoms of Legionnaire’s disease include fever >39oC, anorexia, malaise, myalgia, headache, productive cough, pneumonia, confusion, chills, nausea and diarrhea. The incubation period is usually 2–10 days but can be up to 19 days.

HMC