In March 2020, CDC and state public health officials investigated a multistate outbreak of Salmonella Berta infections. The national cluster code was 2004MLJAX-1. Overall, 13 cases from 10 states were identified in this outbreak. Isolation dates ranged from February 11 to April 25, 2020. Four cases were hospitalized. No deaths were reported.

Three food isolates collected by the US Department of Agriculture Food Safety and Inspection Service were related to the outbreak strain including isolates from pork (n=2) and beef (n=1) with isolation dates from February 14 to April 9, 2020. All clinical and food isolates were related within 0-7 alleles by Whole Genome Sequencing.

Genetic similarity of human, pork, and beef isolates, as well as race and gender demographics, indicated that the cases in the cluster had a common source of infection. However, the outbreak vehicle was not determined.