Summary

The Enteric Reference Laboratory (ERL) typed a total of 957 Yersinia from 1294 cases notified. This includes nine Yersinia pseudotuberculosis isolates, and the remainder were typed as Yersinia enterocolitica. Isolates typed as Y. pseudotuberculosis have been steadily decreasing with 20 in 2019, 13 in 2020, and 10 in 2021. The most common type for the 948 Y. Enterocolitica was biotype 2/3 serotype O:9 with 680 isolates confirmed (71.7%). This is similar to previous years with 669 biotype 2/3 serotype O:9 confirmations in 2021 out of 1077 total isolates. Biotype 1A and biotype 4 serotype O:3 were the next most common types identified with 164 and 76 isolates of the total 948 Y. enterocolitica, respectively (17.3% and 8.0%).