Use of acid-fast bacilli staining to determine the need for airborne infection isolation precautions: a comparison of respiratory specimens.

Institution of appropriate airborne infection isolation (AII) precautions for patients with suspected Mycobacterium tuberculosis is critical to prevent disease transmission. We compared the yield of acid-fast bacilli smears from different types of respiratory specimens and found that smear sensitivity was highest for specimens obtained by endotracheal aspirates (92%), followed by sputum (79%), and then by bronchoalveolar lavage (37%). As a result of this study, our institutional policy regarding discontinuation of AII precautions was amended.