<prompt> Prevalence of TB in a community is estimated by:Tuberculin testAFB smearChest X-RayMontouxtest  <response>: Ans. a Tuberculin testRef: K. Park 23rd ed. 185 Tuberculin Test is the only way of estimating the prevalence of infection in a community. A positive test indicates past or present infection by Mycobacterium tuberculosis. Remember: a positive tuberculin test is NOT a confirmatory diagnostic of M.TB. Sputum smear examination Z-N stain by direct microscopy is the diagnostic choice for TB case detection. Chest X-Ray is a supportive diagnostic test for TB. Montoux test is also a screening test for TB. A positive test indicates current or past infection. 