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': 'First step in epidemic done by an epidemiologist? \nSelect and explain. \nA. Identity the cases, B. Confirm the diagnosis, C. Identify the prone people, D. Identify the causative factors', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Confirmation of diagnosis Steps for Investigation of Epidemic : Verification of diagnosis : Is the first step in investigation of an epidemic' Confirmation of existence of an epidemic: Compare with disease frequencies during same period in previous years Epidemic threshold: An arbitrary limit of '2 standard errors from the endemic occurrence' Defining the population at risk: Obtaining the map of the area Calculation of 'appropriate denominator of population at risk' Rapid search for all cases and their characteristics: Medical survey Epidemiological case sheet Searching for more cases: Search for new cases is carried out everyday, till the area is declared free of epidemic; this period is usually taken as 'twice the incubation period of the disease since the occurrence of last case' Data analysis: Formulation of hypothesis Testing of hypothesis Evaluation of ecological factors Fuher investigation of population at risk Writing the repo", 'role': 'assistant'}]