The probable source of a persistent outbreak of legionaries’ disease that killed four people and sent almost 90 people to the hospital in London, Ontario, has been determined.
The Middlesex-London Health Unit (MLU) said Tuesday that it has coincided with the bacterial subtype that can cause symptoms similar to pneumonia in people with Sofina Foods Inc., a meat processing plant that uses hundreds of workers in the East End of the city.
“During the extensive case investigations, environmental sampling and collaboration with building operators, multiple cooling towers in nine separate locations in London positive for the LEGionELLA LIVE bacteria,” the health unit wrote in a statement. “It was discovered that the results of more evidence in Sofina Foods Inc. coincide with the subtype linked to the outbreak.”
The Health Unit declared the outbreak on August 6 after a period of three weeks in which no new cases were confirmed, said Dr. Joanne Kearon, associate health officer of the Health Unit, in an interview on Tuesday with CBC News.
Since then, however, 25 new cases have emerged, which caused the outbreak to be redec.
“We expected the remediation efforts made by the operators earlier this year to be enough to finish the outbreak, but with several weeks in the heat, the bacteria probably registered and began to transmit again,” Kearon said.
The scope of Mlhu’s investigation that began in early July was vast, and people became ill within a six -kilometer radius throughout the city. At one time, the health unit found positive bacteria within the cooling towers at Victoria Hospital, the largest medical center in the region.
Sofina says that the previous tests showed ‘negative results’
In a statement to CBC News, Sharon Begley, director of Security of Sofina Foods, said the company “is deeply committed to the health and safety of our employees, our products and the community” and will continue working with Mlhu “to completely address their findings.”
“Knowing the robust program and daily tests of safety and sanitation that we have instead, and the negative results of the previous tests, the most recent results” of Mlhu “were unexpected,” said the statement. “We are deeply concerned about this new information and continue to investigate this.”
The statement said that Sofina Foods has been “following Mlhu’s guide and working with our external specialists who have experience in this area and administer our cleaning and maintenance of regular cooling towers.”
“We take immediate measures as soon as Mlhu shared his findings with us. Beyond our regular processes, we carry out more cleaning and disinfection processes recommended by Mlhu.”
The company said the cooling tower is offline and will continue to be until the additional work is completed. “We will continue testing to ensure that any risk has been eliminated.”
More cases are expected due to the incubation period
Legionella is not transmitted from person to person or through eating or drinking. If bacteria are in aerosol or tarnish the air (through wind or fans), people can inhale them and feel bad.
Bacteria occur naturally in the soil and water, and can contaminate and grow in environments that include hydromassage baths, cooling towers, hot water tanks and parts of commercial air conditioning systems, said the health unit.
Most people exposed to Legionella do not get sick, but some may experience the Pontiac fever, a mild disease and similar to the flu that is commonly resolved.
To date, the outbreak has been linked to “serious pneumonia” in at least 94 residents in London, said the health unit. At least 86 have been hospitalized and four have died. Six people remained in the hospital starting Tuesday.
“We continue to receive ongoing cases,” Kearon said. “Legionella has an incubation period of two to 10 days … there may still be more cases in the next two weeks.”
It is not clear how many sofina workers can be among cases or deaths.
“I can’t talk about how many are directly linked to Sofina in terms of working there,” he said. Sofina Foods did not respond to a follow -up consultation.
The health unit began to see new cases “several days” after the outbreak was declared, but it was not clear immediately if they were isolated or linked to the outbreak, he said. Sporadic cases are expected every year, typically five to six in the summer.
“We did not reveal it at that time because we wanted to have time to visit cooling towers before notifying the operators that we would be visiting and that we would require greater disinfection. Disinfection processes can sometimes produce false negatives.”
Take in the afternoonWhat exactly is legionario disease?
An outbreak of Legionars has declared himself in London with one death and more than 40 sick people. Dr. Anna Banerji, a specialist in pediatric infectious diseases at Toronto University, shares her idea of how the propagation and containment of the disease works.
No source had yet been confirmed when the outbreak was initially declared, but Sofina Foods was identified as a probable source after the health unit began to try high risk cooling towers again, Kearon said.
The decision of the health unit to publicly identify the business involved arose from the need to reassure the public and be transparent given the size of the outbreak, he said.
Kearon said Sofina Foods has been cooperating completely through the investigation and had chemically disinfected the cooling towers earlier this summer, something that health officials expected it to be enough.
“However, in cases like this, where the outbreak is so great, there is a risk that there is actually a layer of bacteria that must be physically eliminated from the system. That is what Sofina is currently doing with her contractor,” he said.
“We ensure that a complete physical remediation has occurred, and then we will be continuously testing to ensure that it does not grow again.”
Health officials have also determined that the installation was the probable source of the Legionnaires disease outbreak last year that left two dead people and another 30 patients.
It was discovered that the samples taken from the infected this year have the same subtype seen at last year’s outbreak, he said.
Although other cooling towers within the six -kilometer radius gave positive for Legionella bacteria, only the subtype of bacteria found in Sofina had a coincidence with samples of outbreaks, Kearon said.
