This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
Missing cases are detected by ? 
Select and explain. 
A. Active surveillance, B. Passive surveillance, C. Sentinel surveillance, D. Prevalence rate
C: Sentinel surveillance
Answer: C: Sentinel surveillance 
Explanation: Ans. is 'c' i.e., Sentinel surveillance Surveillance Surveillance is defined as "the continous scrutiny of the factors that determine the occurrence and distribution of disease and other conditions of ill health". Surveillance may be of following types :? 1) Passive surveillance Data is repoed itself to health system, e.g. a patient (clinical case) is coming to a doctor. Most of the national health programmes in India rely on passive surveillance for data collection. 2) Active surveillance Data is collected actively by health system, e.g. collection of blood slides every fonight from house to house to control malaria. Active surveillance in India is done in :- National leprosy elimination programme (modified leprosy elimination campaigns). National vector Borne disease control programme (VVBDCP) e.g. malaria. 3) Sentinel surveillance Sentinel surveillance helps in identifying missing cases and supplementing notified cases. Sentinel surveillance in India is done in national AIDS control programme.