This presentation will describe a 2024 Canadian Listeria monocytogenes outbreak investigation that implicated refrigerated plant-based beverages as the source of illness. While L. monocytogenes outbreaks have previously been linked to pasteurized products, this is the first outbreak linked to pasteurized plant-based beverages. Listeria cannot survive pasteurization, however, contamination can occur during post-pasteurization processing. The evidence that led to implicating plant-based refrigerated beverages as the source of illness will be discussed, as well as outbreak control measures.

Leigh Hobbs is an Epidemiologist Lead with the Enteric Zoonotic and Vector-Borne Diseases (EZVBD) team at Public Health Ontario. Leigh has worked with the EZVBD team since 2013 where she has been involved with numerous enteric outbreak investigations both at the provincial and national levels.