Legionnaires' outbreak that killed two people declared over by MLHU

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An outbreak of Legionnaires' Disease has been declared over by the Middlesex London Health Unit (MLHU).

According to the health unit, between May 1 and Sept. 26, 2024, a total of 30 confirmed legionella cases met the criteria for inclusion in the outbreak.

"The date of symptom onset of the most recent case was Sept. 14. Now that 24 days have passed since any new cases has developed, the outbreak is considered over," read a statement from the health unit.

The people infected by the bacteria ranged in age from 37 to 87 and more than half were men. All 30 people were hospitalized at some point, nine were admitted to the Intensive Care Unit, and two people died. One person remains in hospital.

Despite collecting environmental samples from 18 cooling tower sites, all close to the geographic centre of the cases, the health unit said,"No samples have yet detected legionella bacteria that is a match for that identified in the cases. However, results of the most recent round of tests are still with the Public Health Ontario lab, and it remains possible that a source could be found. If the source is found the community will be informed that the source has been found and sanitized."