Epidemic marker of TB -

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+)