In late December 2016, PulseNet Canada identified a cluster of E. coli O121:H19 infections. The patients resided in geographically distinct provinces. Illness began on dates ranging from November 1, 2016 to April 2017. A total of 30 cases were identified including 1 person from the US who had visited Canada. Eight people were hospitalized. One person developed HUS and recovered. No one died.

In March 2017, E. coli O121 with the outbreak PFGE pattern was isolated from an open flour sample from a patient’s home and a closed sample collected at a retail store, both of the same brand and production date. The clinical and flour isolates grouped together, with only 0–6 whole genome multilocus sequence typing allele differences. As a result of these findings, a product recall was issued.