A new suspect: Listeria monocytogenes outbreak linked to pasteurised plant-based beverages, Canada, 2024

In Canada in 2024, an outbreak of Listeria monocytogenes occurred, linked to pasteurised plant-based dairy alternative beverage products. The outbreak involved 20 confirmed cases (age range: 7–89 years; 13 females, seven males; 14 having underlying medical conditions) and resulted in three deaths. All cases were infected with the same genetic strain of L. monocytogenes . Nineteen of the 20 outbreak-confirmed cases reported consuming the same brand of plant-based beverage product prior to illness onset, and the outbreak strain was found in six open leftover plant-based beverage samples collected from the homes of six outbreak-confirmed cases. All L. monocytogenes -positive food samples were produced at a single manufacturing facility in Ontario, Canada on the same production line. The outbreak strain was confirmed in post-pasteurisation processing areas at the manufacturing facility. However, the source of contamination was not determined. Leftover case–food sample collection by local public health authorities and laboratory testing were instrumental in the timely identification of the outbreak source - a food recall warning was issued within 2 weeks of initial case–food WGS match. Manufacturer adherence to applicable requirements regarding L. monocytogenes in ready-to-eat foods continues to be critical to prevent Listeria contamination and subsequent illnesses and/or deaths.