The source of a persistent outbreak of legionnaires’ disease that’s killed four people and sent more than 90 people to hospital in London, Ont., has been uncovered.
The Middlesex-London Health Unit (MLHU) said Tuesday that it has matched the bacterial subtype that can cause pneumonia-like symptoms in people to Sofina Foods Inc. in the city’s east-end.
The meat-processing plant employs hundreds of workers. CBC News has contacted the company for comment and will update this story if any comment is received.
“During extensive case investigations, environmental sampling and collaboration with building operators, multiple cooling towers at nine separate locations in London tested positive for live legionella bacteria,” the health unit wrote in a statement. “Results from further testing at Sofina Foods Inc. were found to match the subtype linked to the outbreak.”
The scope of the investigation that started in early July was vast, with people getting sick within a six-kilometre radius across the city. At one point, the health unit found positive bacteria inside the cooling towers at Victoria Hospital, the region’s largest medical centre.
The health unit said early this month that the case count had dwindled and the outbreak was over. On Tuesday, however, it said people were getting sick once again.
To date, 94 London residents have been diagnosed with legionnaires’ disease, with 86 hospitalizations and four deaths.
“For several weeks, no additional illnesses were reported, and we were optimistic that remediation efforts had eliminated the bacteria. However, 25 more people have now become ill,” said Dr. Joanne Kearon, associate medical officer of health for the MLHU.
“Fortunately, a likely source has now been identified.”
Legionella is not transmitted from person to person. If the bacteria are aerosolized or misted into the air (via wind or fans), people may inhale them and become unwell. Most people exposed to legionella don’t get ill, but some may experience Pontiac fever, a mild, flu-like illness that commonly resolves itself.
This is the second summer in a row that London has had a legionnaires’ outbreak. In 2024, two people died and 30 were seriously ill.
The MLHU said Sofina Foods has co-operated since the outbreak began and has taken all measures to address the issues.
