Traceback evidence in an outbreak investigation can include which of the following?

• A. Common point of contamination in distribution chain
• B. Inspections identifying safety risks
• C. Both A and B
• D. None of the above

Answer: (C)

Traceback in an outbreak investigation is about reconstructing how a contaminated product moved from its source to consumers and identifying points where the contamination could have entered the process. A common point of contamination found across cases in the distribution chain directly points to where the issue originated or was amplified. At the same time, inspections identifying safety risks—such as sanitation lapses, improper temperature control, or process deviations—help explain how contamination could have occurred and where controls failed. When you combine both types of evidence, you get a clearer, more actionable picture of the outbreak’s source and spread. Therefore, both a shared point in the distribution chain and safety-risk inspections are part of traceback evidence.