Which fields are typically included in a line list for outbreak investigation?

• A. Case ID, age, sex, location, onset date/time, exposure window, clinical features, lab results, vaccination status, outcome
• B. Weather data, stock price, car model
• C. Favorite color, preferred food, shoe size
• D. Genetic sequence data only

Answer: (A)

Line lists are the structured tabular records used in outbreak investigations to document each diagnosed or suspected case and track how the outbreak unfolds. They provide a complete, comparable snapshot of who is affected, when and where cases occur, and how they progress, which is essential for identifying transmission patterns and potential exposures.

The best set of fields includes unique case identifiers, basic demographics, location, timing, exposure window, clinical features, laboratory findings, vaccination status, and outcome. A unique case ID lets you link all information for the same person without duplication. Age and sex describe the population affected and help detect age- or sex-specific patterns. Location ties cases to geographic areas, which is crucial for mapping spread. Onset date and time anchor the temporal sequence, enabling the creation of epidemic curves and trend analysis. The exposure window focuses on when exposure likely occurred, guiding hypothesis generation about sources and routes of transmission. Clinical features summarize symptoms and severity, supporting case definitions and comparisons across cases. Lab results provide diagnostic confirmation and help distinguish the outbreak pathogen from other illnesses. Vaccination status informs susceptibility and potential vaccine effectiveness within the group. Outcome tracks what happened to cases, including recovery or progression to severe disease, which matters for assessing outbreak impact.

Other data types like weather data, stock prices, or personal preferences do not contribute to identifying transmission dynamics or guiding public health actions in an outbreak. Genetic sequence data can be valuable in deeper analyses, but it does not replace the need for a complete, case-level line list that includes demographics, timing, exposure, and clinical information.