Which data element is NOT typically included in a standard outbreak line list?

• A. Case ID
• B. Onset date
• C. Exposure history
• D. Vaccination status

Answer: (D)

Outbreak line lists are designed to track cases quickly and reveal how the illness spreads. The most useful fields are those that identify each person, show when they became ill, and indicate how they might have been exposed. A Case ID gives a unique reference for every patient, Onset date establishes the outbreak’s timeline so you can see how cases accumulate over time, and Exposure history helps connect cases to a common source or setting. Vaccination status, while important for understanding immunity and vaccine effectiveness, doesn’t drive the immediate outbreak tracing or transmission picture in a standard line list. It’s usually stored separately or used in a focused vaccine-related analysis rather than in the core line list. So vaccination status is not typically included in a standard outbreak line list, though it can be added if the investigation specifically needs it.