The Public Health Agency of Canada says it was only after multiple Listeria cases emerged in Ontario in June that it recognized a broader outbreak that had started back in August 2023.

Questions have swirled around why it took nearly a year for the Canadian Food Inspection Agency to announce a national recall of several Silk and Great Value plant-based milk products on July 8.

The federal agency says it became aware of two genetically related listeriosis cases — the illness caused by Listeria bacteria — in September 2023, but knew of no common food exposure.

PHAC spokesperson Anna Maddison says it was only when several cases in Ontario were reported in June 2024 and a provincial investigation was launched that the connection was made.

There have been three deaths in Ontario linked to the outbreak, which has also infected individuals in Quebec, Nova Scotia and Alberta.

The source of the illness was traced to a specific production line at a third-party beverage packaging facility in Pickering, Ont., used by plant-milk manufacturer Danone Canada.

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This report by The Canadian Press was first published Aug. 15, 2024.

Hannah Alberga, The Canadian Press