Laboratory practices for diagnosis of tuberculosis--United States, 1994.

The increase in cases of tuberculosis (TB) during 1985-1992 and the emergence of multidrug-resistant Mycobacterium tuberculosis strains led to recommendations for rapid laboratory testing to support control efforts and selection of proper therapy (1,2). Many laboratories have adopted the recommendations to use rapid acid-fast bacilli (AFB) smears, growth detection (i.e., primary culture), identification, and drug-susceptibility testing for M. tuberculosis (3). The regulations implementing the 1988 Clinical Laboratory Improvement Amendments* (CLIA) require all laboratories that perform any mycobacteriology testing to enroll in federally approved proficiency testing (PT) programs. This report summarizes information reported by the laboratories to PT programs in the United States about their practices for M. tuberculosis.