Health officials connect Listeria outbreak to recalled plant-based milk, prompting national concerns
The federal health agency was only able to identify the source of a Listeria outbreak, now linked to three deaths and 20 infections, after a cluster of cases emerged in Ontario.
As reported by CTV News, the outbreak, which has led to a national recall of several Silk and Great Value plant-based milk products, was first noticed after the Canadian Food Inspection Agency’s recall announcement on July 8.
However, the process to remove affected products from store shelves has raised questions due to the nearly year-long delay in identifying the source.
Health experts suggest that several factors may have complicated efforts to trace the outbreak, including the rarity of Listeria in plant-based beverages and the long incubation period of listeriosis, the illness caused by Listeria bacteria.
Lori Burrows, a microbiologist at McMaster University, explained that identifying such outbreaks is akin to solving an “epidemiological puzzle,” where various pieces must fit together before the full picture becomes clear.
The Public Health Agency of Canada (PHAC) revealed that it first became aware of two genetically related listeriosis cases in September 2023 but could not link them to a common food source at the time.
It wasn’t until nine cases surfaced in Ontario in June 2024 that a provincial investigation connected the dots. According to PHAC spokesperson Anna Maddison, investigators then re-contacted the 2023 cases and found that they, too, had consumed the implicated beverages.
As of the most recent update, 20 cases have been confirmed across Canada, including infections in Ontario, Quebec, Nova Scotia, and Alberta. Ontario has reported three deaths linked to the outbreak, two of which occurred in Toronto, according to the city’s public health agency.
The contamination was traced back to a specific production line at a third-party beverage packaging facility in Pickering, Ontario, used by Danone Canada, the manufacturer of the Silk and Great Value plant-based milk products.
The facility was shut down on July 6, and production has been halted since. Jennifer Vincent, Danone's head of communications, stated that the company is intensifying testing of all refrigerated products at its other facilities and has enlisted independent experts to aid in the investigation.
A timeline on the PHAC website shows that the first case was reported in August 2023, followed by another in September and a third in December. The surge of nine cases occurred in June 2024, with eight more reported in July.
Lawrence Goodridge, a professor at the University of Guelph and Canada research chair in foodborne pathogen dynamics, noted that Listeria outbreaks are challenging to identify quickly because symptoms can take up to 70 days to emerge, making it difficult for individuals to recall what they ate.
The recall affects Silk almond milk, coconut milk, almond-coconut milk, oat milk, almond-cashew milk, and Great Value almond milk, with best-before dates up to and including October 4, and containing the product code 7825.
Burrows emphasized that Listeria contamination in plant-based beverages is unusual, as these products are often perceived as healthy alternatives. Goodridge added that this outbreak is the first time almond milk has been linked to Listeria or any foodborne illness.
Vincent confirmed that Silk’s refrigerated plant-based beverages have returned to retail shelves after production resumed at other facilities.
She expressed the company's regret, stating, “We're still undergoing the investigation. We're obviously very saddened that this happened. We're sorry that this happened.”
