Use of nucleic acid amplification testing for rapid detection of Mycobacterium tuberculosis complex among U.S. tuberculosis patients from 2011‒2017

Abstract

Background Nucleic acid amplification (NAA) tests rapidly detect Mycobacterium tuberculosis complex directly from clinical specimens, providing valuable results for those evaluated for tuberculosis. Methods We analyzed characteristics of cases with NAA testing performed, compared cases with positive and negative NAA test results, and calculated turnaround time and time-to-treatment for all verified cases reported to the National Tuberculosis Surveillance System in the United States during 2011–2017. Results Among 67,082 verified tuberculosis cases with NAA testing information, 30,820 (45.9%) were reported as not having a NAA test performed; the proportion without NAA testing declined annually, from 60.5% in 2011 to 33.6% in 2017. Of 67,082 verified cases, 27,912 (41.6%) had positive, 8,215 (12.2%) had negative, and 135 (0.2%) had indeterminate NAA test results. Among the 33,937 cases with an acid-fast-bacilli–smear-positive result, 70.9% (24,093) had a NAA test performed; 38.0% (11,490) of the 30,244 with an acid-fast-bacilli–smear-negative result had a NAA test performed. Although sputum was the most common specimen type tested, 79.8% (7,023 of 8,804) of non-sputum specimen types had a positive NAA test result. Overall, 63.7% of cases with laboratory testing had NAA test results reported <6 days following specimen collection; for 13,891 cases not yet on treatment, median time-to-treatment after the laboratory report date was 2 days. Conclusions Our analyses demonstrate increased NAA test utilization between 2011 and 2017. However, a large proportion of cases did not have a NAA test performed, reflecting challenges in broader uptake, suggesting an opportunity to expand use of this diagnostic methodology.

Second Time's the Charm? Assessing the Sensitivity and Yield of Inpatient Diagnostic Algorithms for Pulmonary Tuberculosis in a Low-Prevalence Setting

“…Despite the higher sensitivity of NAATs over AFB smears, NAATs are still underutilized, largely due to concerns regarding cost [ 16 ], which limit their availability in health care facility–based laboratories. NAATs can detect M tuberculosis within hours, much earlier than mycobacterial cultures, which usually require 2 to 8 weeks to grow [ 6 , 24 ].…”

“…AFB smear microscopy is not feasible for many hospital laboratories that are already facing unprecedented staffing challenges [ 15 ], so these specimens are often sent to reference laboratories, potentially contributing to delays in care. Conversely, NAAT platforms, which are increasingly available in clinical laboratories [ 16 ], are less labor intensive but have higher up-front costs than microscopy [ 11 ], limiting their availability in some health care settings. AFB smears and culture provide value beyond NAATs, including detection of nontuberculous mycobacteria and estimation of the overall bacillary burden, which inform the duration of infectiousness of individuals with tuberculosis, the contact investigations, and the treatment decisions [ 17 ].…”

Quadriplegia Following Prevertebral/Retropharyngeal Collection Secondary to Extrapulmonary Spinal Tuberculosis (Pott’s Disease)

“…As a result, nucleic acid amplification testing is gaining popularity by directly detecting the DNA or RNA in sputum. It provides rapid diagnosis within eight hours [ 8 ].…”