Product Tracing in Epidemiologic Investigations of Outbreaks due to Commercially Distributed Food Items Utility, Application, and Considerations. The effective use of product tracing as part of epidemiologic investigations has been demonstrated in numerous foodborne disease outbreaks. However, the approaches and systems used to conduct product tracing in this context have not been standardized, and the application of this critical tool has not kept pace with the growing number and complexity of cluster investigations. This document attempts to summarize the rationale for conducting product tracing as part of epidemiologic investigations, how product tracing fits in with the rest of an investigation, how it can be conducted most efficiently and effectively, and barriers to its use. Local and state agencies, including public health, environmental health, and agriculture agencies, are a primary focus of this document. However, because most pertinent outbreaks will be multi-jurisdictional, the federal public health and regulatory agencies also are primary intended audiences because they also are critical collaborators.