Reporting of diseases is a type of which surveillance?

• A. Active
• B. Passive
• C. Syndromic
• D. Sentinel

Answer: (B)

The main idea here is that disease reporting to health authorities is an example of passive surveillance. In this approach, the information comes from outside sources—clinicians and laboratories—who report diagnosed cases to public health agencies, often because it’s required by law or policy (notifiable diseases). The public health agency isn’t actively going through records to find every case; instead, it relies on providers to submit reports, which can lead to wide coverage but slower, sometimes incomplete data.

If it were active surveillance, public health officials would be actively seeking out cases—reviewing records, contacting facilities, and prompting reporting themselves. Syndromic surveillance, on the other hand, watches for patterns of symptoms (like fever and malaise) to detect possible outbreaks before diagnoses are confirmed. Sentinel surveillance uses data from selected sites to monitor trends rather than reporting from every location. Because reporting diagnosed diseases fits the model of information flowing in from providers to authorities rather than the agency actively searching, this is passive surveillance.