Outbreak investigations of and frozen raw breaded chicken: the mitigation of a significant public health issue in Canada.

In May 2017, whole-genome sequencing (WGS) became the primary subtyping method for in Canada. As a result of the increased discriminatory power provided by WGS, 16 multi-jurisdictional outbreaks of associated with frozen raw breaded chicken products were identified between 2017 and 2019. The majority (15/16) were associated with , while the remaining outbreak was associated with Heidelberg. The 16 outbreaks included a total of 487 cases with ages ranging from 0 to 98 years (median: 24 years); 79 hospitalizations and two deaths were reported. Over the course of the outbreak investigations, 14 frozen raw breaded chicken products were recalled, and one was voluntarily withdrawn from the market. After previous changes to labelling and the issuance of public communication for these products proved ineffective at reducing illnesses, new industry requirements were issued in 2019, which required the implementation of measures at the manufacturing/processing level to reduce to below detectable amounts in frozen raw breaded chicken products. Since implementation, no further outbreaks of associated with frozen breaded chicken have been identified in Canada, a testament to the effectiveness of these risk mitigation measures.