TORONTO (Reuters) - A food poisoning outbreak that has killed four Canadians and sickened at least 21 others has been genetically linked to meat produced at a plant owned by Maple Leaf Foods Inc, authorities said on Saturday.
The company, one of Canada’s biggest meat processors, had been considered the likely source of the deli-style meat that had been contaminated by listeria bacteria.
Maple Leaf had already voluntarily recalled more than 20 varieties of meat products made at its Toronto plant in June.
On Saturday, it extended the recall to all products from the plant, which has stopped production.
Most of the products were sold to restaurants, including McDonald’s Corp, as well as to hospitals, nursing homes and deli counters in several Canadian provinces.
The products were not exported.
Listeriosis is particularly dangerous for pregnant women, the elderly, infants, and people with weak immune systems. Three deaths were in Ontario and one in British Columbia.
Listeria bacteria are common, and a minuscule amount coming into contact with deli meats can thrive and multiply, even in a refrigerator, health authorities say.
The Public Health Agency of Canada, which announced the results of genetic tests that linked the Maple Leaf plant to the outbreak, said the results suggested the investigation was on the right path but far from complete.
So far, 21 cases of listeriosis have been confirmed in four provinces, and the same strain has been detected in four people who have died. A further 30 cases are under investigation.
“Because the onset of symptoms of listeriosis can occur up to 70 days after contaminated food is consumed, it is expected that the number of confirmed and suspected cases will continue to increase over the next several weeks,” the agency said.
Maple Leaf Chief Executive Michael McCain later told a news conference his company had one of the most comprehensive health and safety systems in North America, “above and beyond” what was required by regulators.
But he said that listeria was particularly difficult to detect and prevent.
Since the initial recall, the company has recalled all production from the plant, which will remain closed for sanitization until at least early next week, he said.
He declined to provide an estimate of the costs or losses the company is facing. Maple Leaf shares dropped 4.6 percent to C$9.80 on Friday.
Reporting by Ted Kerr; Editing by Peter Cooney