The challenge of linking Listeria cases to some plant-based milks
It wasn’t until a cluster of Listeria cases emerged in Ontario that the federal health agency says it was able to find the source of an outbreak that’s now linked to three deaths and 20 infections.
Ever since the Canadian Food Inspection Agency announced a national recall of several Silk and Great Value plant-based milk products on July 8, questions have swirled around why it took nearly a year to pull affected products from store shelves.
Health experts say multiple factors likely complicated efforts to identify the origins of this particular outbreak, including the relative rarity of finding Listeria in plant-based beverages and the long incubation period of listeriosis cases — the illness caused by Listeria bacteria.
“It’s an epidemiological puzzle and you need to put the pieces together before you can start to see the picture,” says Lori Burrows, a microbiologist at McMaster University in Hamilton.

