Middlesex-London Health Unit is providing an update to the community on the ongoing outbreak of Legionnaires’ Disease following the holiday long weekend.
Since our last update on Friday August 2, there have been two additional cases of Legionnaires’ Disease identified as part of the outbreak. This brings the total number of cases to 24. The number of individuals currently hospitalized has decreased to 4. There have been no additional fatalities.
The MLHU Environmental Health Team is working under the guidance of Public Health Ontario on a sampling plan to isolate the source of legionella that led to the outbreak. Over the past ten days, 10 samples were taken from within the geography where most cases live or work. To date, evidence of legionella bacteria has been found in three of the cooling towers in the testing region.
Samples from each of these sites were sent to the Public Health Ontario Labs to be cultured. This process, which takes approximately 10 days, will allow MLHU to determine which site, if any, is linked with the current outbreak. MLHU expresses its appreciation for local businesses for their cooperation with the investigation, and all sites where evidence of the legionella bacteria was found for quickly moving toward remediation to eliminate the risk to the public.
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.
In the meantime, Middlesex-London Health Unit asks all business owners and property managers to ensure that all cooling equipment is regularly maintained and sanitized as per the manufacturer’s instructions. This is the best way to reduce the risk of further legionella outbreaks.
The Middlesex-London Health Unit will next provide an update on the afternoon of Monday August 12.