NAA tuberculosis guidelines

In August 2013, the Food and Drug Administration (FDA) permitted marketing of the Xpert MTB/RIF assay (Cepheid, Sunnyvale, California) to detect DNA of the Mycobacterium tuberculosis complex (MTBC) and genetic mutations associated with resistance to rifampin (RMP) in unprocessed sputum and concentrated sputum sediments. Along with clinical, radiographic, and other laboratory findings, results of the assay aid in the diagnosis of pulmonary tuberculosis (TB). The assay is a nucleic acid amplification-based (NAA)* test using a disposable cartridge in conjunction with the GeneXpert Instrument System...

Tuberculosis is still a major health problem in industrialized countries due to specific socioeconomic factors and there is the growing need of new rapid and accurate diagnostic methods, in order to achieve higher sensitivity and specificity compared to traditional methods of microscopic sputum examination and culture. Such methods, recently introduced, are nucleic acid amplification (NAA) tests, used directly on clinical specimens and blood tests (QuantiFERON-TB, T-SPOT.TB test), measuring the IFN-gamma released by stimulated T cells...

Guidelines for the use of nucleic acid amplification (NAA) tests for the diagnosis of tuberculosis (TB) were published in 1996 and updated in 2000. Since then, NAA testing has become a routine procedure in many settings because NAA tests can reliably detect Mycobacterium tuberculosis bacteria in specimens 1 or more weeks earlier than culture. Earlier laboratory confirmation of TB can lead to earlier treatment initiation, improved patient outcomes, increased opportunities to interrupt transmission, and more effective public health interventions...

Use of the most rapid and reliable laboratory tests for mycobacterial detection, identification, and susceptibility testing is important for TB control. In 1993, CDC experts made recommendations regarding optimal methods of mycobacterial testing (i.e., stains for AFB, culture, identification, and susceptibility testing of M. tuberculosis) and turnaround times for reporting results. Various technical advances have enhanced the diagnostic capability of the laboratory and/or improved laboratory efficiency since then...

Traditional methods for laboratory diagnosis of tuberculosis (TB) may require weeks, and delay can impede treatment and control efforts. Nucleic acid amplification (NAA) tests, such as polymerase chain reaction (PCR) and other methods for amplifying DNA and RNA, may facilitate rapid detection of microorganisms. An NAA test for Mycobacterium tuberculosis complex (Amplified Mycobacterium Tuberculosis Direct Test of MTD [Gen-Probe, San Diego, California]) was recently approved by the Food and Drug Administration (FDA) for use on processed clinical specimens, and others are under development...