Use of Nucleic Acid Amplification Tests in Tuberculosis Patients in California, 2010–2013

Abstract

Background.Nucleic acid amplification tests (NAATs) have been used as a diagnostic tool for tuberculosis (TB) in the United States for many years. We sought to assess NAAT use in TB patients in California during a period of time when NAAT availability increased throughout the world.Methods.We conducted a retrospective review of surveillance data from 6051 patients with culture-confirmed pulmonary TB who were reported to the California TB registry during 2010–2013.Results.Only 2336 of 6051 (39%) TB patients had a NAAT for diagnosis before culture results. Although 90% (N = 2101) with NAAT had positive test results, 9% (N = 217) had falsely negative NAAT results, and 0.8% (N = 18) had indeterminate NAAT results. The median time from specimen collection to TB treatment initiation was shorter when NAAT was used (3 vs 14 days, P < .0001), and patients with a positive NAAT result initiated treatment earlier than patients with a falsely negative result (1 vs 11 days from NAAT report, P < .0001). We confirmed the increased sensitivity of NAAT compared with acid-fast bacilli (AFB) smear microscopy in our study population; 92 of 145 AFB smear-negative patients had positive NAATs. Median time from specimen collection to NAAT result report differed by health jurisdiction, from 1 to 11 working days.Conclusions.Increased use of NAATs in diagnosis of pulmonary TB could decrease the time-to-treatment initiation and consequently decrease transmission. However, differential use and access to NAAT may prevent full realization of NAAT benefits in California.

Unsuccessful Xpert® MTB/RIF results: the Nigerian experience

“…Today, diagnostic decisions on both drug-susceptible (DS-TB) and rifampicin (RMP) resistant TB (RR-TB) can be made within 2 h of sample collection, thus significantly reducing the lag time for diagnosis and facilitating prompt clinical decision making, which benefits TB control. 4,5 Following the World Health Organization's (WHO's) endorsement of Xpert, many countries, including Nigeria, embraced this technology with optimism. 6 It is the first simple TB molecular test that is robust enough to be introduced outside conventional laboratory settings.…”

Impact of nucleic acid amplification test on pulmonary tuberculosis notifications and treatments in Taiwan: a 7-year single-center cohort study

“…Theoretically, NAATs can shorten the time taken to initiate treatments in patients with PTB. Several studies using different definitions of the starting time reported a reduced time to treatment initiation [11, 12]. Utilization of NAAT(Gen-Probe) has shown an impact on treatment decisions in California, USA [11]; the median time from specimen collection to initiation of TB treatments was shorter (3 days vs 14 days) with the use of NAAT (Gen-Probe).…”

“…Several studies using different definitions of the starting time reported a reduced time to treatment initiation [11, 12]. Utilization of NAAT(Gen-Probe) has shown an impact on treatment decisions in California, USA [11]; the median time from specimen collection to initiation of TB treatments was shorter (3 days vs 14 days) with the use of NAAT (Gen-Probe). With regard to multidrug-resistant tuberculosis (MDRTB), a retrospective study in India has reported that the use of NAAT(Hain) reduced the median time from identification of patients suspected to have MDRTB to initiation of treatments from 157 days to 38 days [12].…”

“…Many studies have highlighted the importance of NAATs. Use of these tests enable the reduction of unnecessary airborne isolation [9, 10], shorter duration of unnecessary anti-TB treatment [9, 10], and shorter delays to treatment initiation [11, 12]. In this study, the impact of NAAT using E-MTD (Gen-Probe, San Diego, CA, USA) [NAAT(Gen-Probe)] at a single center over a period of 7 years was retrospectively assessed; the following aspects were investigated: whether NAAT(Gen-Probe) (i) reduced error notifications of suspected cases of TB to Taiwan CDC; (ii) avoided administration of unnecessary anti-TB treatments; (iii) reduced the duration of unnecessary anti-TB treatments; and (iv) hastened treatment initiation.…”

Clinical Impact of Nucleic Acid Amplification Testing in the Diagnosis of Mycobacterium Tuberculosis: A 10-Year Longitudinal Study

“…In 1995, nucleic acid amplification tests (NAATs) were initially approved to be performed on respiratory specimens from patients with smear-positive AFB and clinical features of tuberculosis (TB). Nucleic acid amplification test sensitivity and specificity in diagnosing MTB has been reported to be as high as 99% and 98%, respectively [ 4 , 5 ], resulting in a higher MTB detection rate and shorter time to treatment initiation [ 6 ]. Nucleic acid amplification tests of respiratory specimens from patients with suspected pulmonary TB has been recommended by the US Centers for Disease Control and Prevention (CDC) [ 7 ].…”