This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Tuberculosis, 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 rate o Case finding tools in TB are :-1) Sputum microscopy# It is the method of choice2) Sputum culture# It is 2nd in importance (after sputum microscopy) in a case finding programme.3) Mass miniature radiography# It has been stopped as a general measure of case finding.4) Tuberculin test# It is of little value as a case finding tool as it has no diagnostic value.o The number of bacilli seen in a smear reflects disease severity and patient infectivity.o Therefore, it is important to record the number of bacilli seen in each smear.Number of bacilliResult reportedNo. AFB per 100 oil immersion fields01-9 AFB per 100 oil immersion fieldsScanty (or number AFB seen)10-99 AFB per 100 oil immersion fields+ (1+)1-10 AFB per oil immersion fields++ (2+)> 10 AFB per oil immersion fields+++ (3+)", 'role': 'assistant'}]