The focus of the study was Sample-Initiated Retrospective Outbreak Investigations (SIROIs), which are initiated by the recovery of pathogenic microbial isolates from food product or environmental samples, followed by the identification of a cluster of genetically related clinical isolates, with subsequent epidemiologic and traceback investigations confirming a link between a suspect vehicle and illnesses. SIROIs, which are used by used by federal public health and regulatory partners in the U.S., are enabled by the increasing use of whole genome sequencing (WGS) for isolates of foodborne pathogens, as well as the ability to share and compare data on public platforms.