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
[{'content': 'Measures involved in sentinel surveillance include all except \nSelect and explain. \nA. Identifying cases free of disability, B. Identifying new cases of infection, C. Identifying old cases and new cases of infection, D. Identifying missing cases in notification of disease', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Surveillance: Is the ongoing systematic collection and analysis of data and the provision of information which leads to action being taken to prevent and control a disease, usually one of an infectious nature\nSurveillance is of many types:\nPassive Surveillance: Data is itself reported to the health system; For e.g., A patient with fever coming on his own to the PHC, CHC, Dispensary, Private Practitioner, Hospital\nActive Surveillance: Health system seeks out ‘actively’ the collection of data, i.e., goes out to community to collect data; For e.g., Stool sample collection from home in Polio Program.\nSentinel Surveillance: Monitoring of rate of occurrence of specific conditions to assess the stability or change in health levels of a population, It is also the study of disease rates in a specific cohort, geographic area, population subgroup, etc. to estimate trends in larger population; For e.g., Use of health practitioners to monitor trends of a health event in a population\n\n\nSentinel Surveillance helps in ‘identifying missing cases’ and ‘supplementing notified cases’', 'role': 'assistant'}]