Which form of surveillance is described as a collection of symptoms?

• A. Laboratory-based surveillance
• B. Active surveillance
• C. Syndromic surveillance
• D. Passive surveillance

Answer: (C)

Syndromic surveillance focuses on collecting and analyzing data about symptoms or symptom patterns (syndromes) rather than waiting for confirmed diagnoses. This approach looks for clusters of symptoms—such as fever with cough, or vomiting and diarrhea—across populations in near real time, which allows public health officials to spot potential outbreaks sooner, before laboratory confirmation is available. Data sources often include emergency department chief complaints, urgent care visit notes, school absences, and even over-the-counter medication sales, all grouped into syndromes to detect unusual increases.

This is different from laboratory-based surveillance, which depends on diagnosed and lab-confirmed cases; active surveillance, which involves proactive, targeted data collection; and passive surveillance, which relies on routine reports that may miss early signals. The essence of syndromic surveillance is monitoring symptoms themselves to generate timely signals of possible health events.