Which statement describes event-driven surveillance example?

• A. It relies on routine lab-confirmed data to signal outbreaks.
• B. It uses weekly summaries from clinics.
• C. It uses reports of unusual health events from media or hotlines to identify signals; e.g., fever clusters.
• D. It relies on annual surveys.

Answer: (C)

Event-driven surveillance relies on reports of unusual health events from media, hotlines, or other informal sources to identify signals of potential outbreaks. The statement captures this idea by pointing to reports from media or hotlines to detect signals like fever clusters, which can prompt rapid verification and investigation. This approach contrasts with routine surveillance, which depends on predefined data streams such as lab-confirmed cases or regular clinic summaries, and with annual surveys that provide data on a longer, less responsive timescale.