Question

Missing cases are detected by?

• A. Active surveillance
• B. Passive surveillance
• C. Sentinel surveillance
• D. Prevalence rate

Hint:

It uses select reporting sites to supplement notified cases and pick up the ones that slip through.

Answer 1

The Correct Option is C

Step 1: Surveillance is the continuous scrutiny of the factors that determine the occurrence and distribution of disease and other conditions of ill health. It is carried out in several forms.

Step 2: Sentinel surveillance is used to identify missing cases and to supplement notified cases. It samples selected reporting sites to estimate the true burden when routine notification is incomplete. In India it is used in the National AIDS Control Programme. So option c is correct.

Step 3: In passive surveillance the data report themselves to the health system, for example when a patient comes to a doctor; most national health programmes in India rely on it. In active surveillance the health system actively collects data, for example house-to-house blood slide collection for malaria. Neither is specifically meant to pick up missing cases.

Step 4: Prevalence rate (option d) is a measure of disease frequency, not a method of case detection. Hence the answer is sentinel surveillance.