Middlesex-London Health Unit is providing an update to the community on the ongoing outbreak of Legionnaires’ Disease.

Since our last official update on Wednesday August 7, 2024 there has been one additional case, bringing the total number connected with the update to 25. Four people remain hospitalized. There have been no further fatalities.

MLHU has not yet had the source of the outbreak confirmed through laboratory testing, however any locations that show evidence of legionella bacteria through preliminary testing have been sanitized - removing any threat to the community.

Legionnaires disease is a respiratory illness caused by a bacteria called Legionella. It is characterized by high fever, chills, a dry cough, shortness of breath and can lead to pneumonia. Symptoms of Legionnaires usually begin two to ten days after encountering the bacteria.

Legionella bacteria are very commonly found in the environment, usually in water (hot tubs, cooling towers, hot water tanks, large plumbing systems or parts of an air-conditioning system). If the bacteria are then aerosolized or misted into the air (via wind or fans), humans may breathe them in and become unwell. Legionella is not transmitted from person-to-person, through public waterworks, or through the consumption of contaminated foods.

To learn how to prevent the growth of Legionella bacteria in your home, please review the instructions on our new tip sheet, “Preventing Legionnaires’ Disease at Home.” To prevent Legionella bacteria in larger industrial settings, owners and property managers should follow the manufacturers instructions for cleaning and maintaining large plumbing systems.