In an investigation of a listeriosis outbreak in Ontario, Canada, during November 2015-June 2016, pasteurized chocolate milk was identified as the source. Because listeriosis outbreaks associated with pasteurized milk are rare in North America, these findings highlight that dairy products can be contaminated after pasteurization.
Keywords: Canada; Listeria monocytogenes; Ontario; bacteria; chocolate milk; enteric infections; food safety; listeriosis; outbreak; pasteurization; pulsed-field gel electrophoresis; whole-genome sequencing.