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': 'Epidemic marker of TB ? \nSelect and explain. \nA. Sputum AFB positivity rate, B. Tuberculin test positivity rate, C. Chest x-ray positivity rate, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. is \'a\' i.e., Sputum AFB Positivity rateCase finding tool of choice for TB is suptum microscopy 4 sputum AFB positivityCase finding tools in TB are :?Sputum microscopyIt is the method of choice.Sputum cultureIt is 2" in impoance (after sputum microscopy) in a case finding programme.Mass miniature radiographyIt has been stopped as a general measure of case finding.4) Tuberculin testIt is of little value as a case finding tool as it has no diagnostic value.The number of bacilli seen in a smear reflects disease severity and patient infectivity.Therefore, it is impoant to record the number of bacilli seen in each smear.', 'role': 'assistant'}]