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': 'Regarding point source epidemic, false statement (s) is/are:a) Rapid rise & fallb) Only infectious disease can causec) Explosived) Cases occur even after incubation periode) No secondary wave \nSelect and explain. \nA. ce, B. bd, C. cde, D. eb', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Features of point source (single exposure) epidemics \n\nThe exposure to the disease agent is brief and essentially simultaneous → single exposure.\nBecause disease agent enters into all exposed persons at same time → the resultant cases all develop within one incubation period of the disease.\nThe epidemic curve rises and falls rapidly.\nBecause exposure is single (simultaneous) with no further exposure → No secondary wave (no secondary case).\nEpidemic tends to be explosive, there is clustering of cases within a narrow interval of time.\nPoint source epidemics are mostly (not always) due to exposure to an infectious agent.\nExamples → Food poisoning, Bhopal gas tragedy, Minamata disease in Japan, Chernobyl tragedy.', 'role': 'assistant'}]