This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infectious Disease Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'What is true about isolation period of enteric fever: \nSelect and explain. \nA. Till three bacteriologically negative stools and urine reports, B. Upto three days after starting the treatment, C. Till the fever subsides, D. Till Widal becomes negative', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e. Till three bacteriologically negative stools and urine reports To prevent the spread of infection, the patients are kept in isolation till three bacteriologically negative stools and urine reports, are obtained on three separate days.Recommended periods of isolationChicken pox - Until lesions have dried and crusted, or until no new lesions appear, usually by the fifth day.Measles - For a week from the onset of rashMumps - till 5 days after the onset of parotitisDiphtheria - All cases, suspected cases and carriers should be promptly isolated, for at least 14 days or until proved free of infection. At least 2 consecutive nose and throat swabs, taken 24 hours apart, should be negative before termination isolation.", 'role': 'assistant'}]