Nucleic Acid Amplification Test Considerations—Tuberculosis

NAATs have improved the diagnosis of TB, particularly in developing nations with high prevalences of TB. Traditionally, TB is diagnosed through direct microscopy of stained sputum smears, although this method has low sensitivity (~50 to 60%), or through culture, which is a suboptimal gold standard because it takes days or weeks to obtain results (Dheda et al. 2013). Nucleic acid tests for TB have high sensitivity (~98% in smear-positive patients and ~75% in smear-negative patients) and can deliver results within 2 hours, which could allow the physician to initiate treatment for the patient the same day as the healthcare visit (Dheda et al. 2013). POC nucleic acid tests for TB are rapid, sensitive, and specific and have the potential to replace smear microscopy. Nucleic acid tests also have the ability to identify multidrug-resistant TB (resistant to at least isoniazid and rifampin, two of the first-line therapeutic agents).