Near point-of-care nucleic acid amplification tests (NPOC-NAATs) using respiratory specimens for detection of pulmonary tuberculosis

RATIONALE: Near point-of-care nucleic acid amplification tests (NPOC-NAATs) are a new class of diagnostics that can be used for tuberculosis diagnosis. NPOC-NAATs are suitable for use in peripheral levels of healthcare systems as they are battery-operated instrument-based tests without special infrastructure requirements and can be performed by health care workers with basic technical skills. We evaluated the accuracy of NPOC-NAATs in diagnosing pulmonary tuberculosis using respiratory samples. OBJECTIVES: To assess the diagnostic accuracy of NPOC-NAATs for detecting pulmonary tuberculosis using respiratory samples from adults, adolescents, and children with presumptive tuberculosis based on signs or symptoms or a positive diagnostic screening result. Secondary objectives included: 1) to compare the diagnostic accuracy of NPOC-NAATs versus smear microscopy or low complexity, automated nucleic acid amplification tests (LC-aNAATs) for detecting pulmonary tuberculosis using respiratory samples from adults, adolescents, and children; 2) to investigate potential sources of heterogeneity such as smear status, Xpert MTB/RIF Ultra semi-quantitative category, HIV status, age groups, and history of tuberculosis; 3) to summarise the frequency of inconclusive (invalid, error, no result, and indeterminate) index test results. SEARCH METHODS: We searched seven databases including CENTRAL, MEDLINE, and Embase, plus two trial registers (ClinicalTrials.gov and the WHO ICTRP) between 21 and 25 July 2025, without language restrictions. A World Health Organization (WHO) Public Call for ongoing and unpublished studies was made between 29 May and 15 July 2025. In consultation with the WHO, we searched for studies published since 2024 to reflect the development dates of relevant tests. ELIGIBILITY CRITERIA: We included studies that provided data on the diagnostic accuracy of NPOC-NAATs that met our criteria using respiratory specimens in children (less than 10 years old), adolescents (aged 10 to 14 years), and adults (aged 15 years and older) with presumptive pulmonary tuberculosis. The reference standards were culture and a composite reference standard that included culture or the clinical decision to treat. RISK OF BIAS AND APPLICABILITY: We assessed the risk of bias using the Quality Assessment of Studies of Diagnostic Accuracy - Revised (QUADAS-2) and QUADAS-C tools. SYNTHESIS METHODS: Working in pairs, we independently extracted data using a standardised form. We used a bivariate model for the meta-analyses to estimate summary sensitivities and specificities for pulmonary tuberculosis detection. We performed subgroup analyses by smear status and HIV status. We conducted head-to-head comparisons of the accuracy of NPOC-NAATs with those of LC-aNAATs and sputum smear microscopy. INCLUDED STUDIES: We included five studies that enrolled a total of 3291 participants. Study participants were from nine countries, all of which have a moderate to high tuberculosis burden. All studies assessed the diagnostic accuracy of one design-locked and marketed NPOC-NAAT that met WHO criteria: the MTB NAT Card analysed using the battery-powered Pluslife Thermolyse and MiniDock (Minidock) devices. The only specimen type with available data was sputum. SYNTHESIS OF RESULTS: For detection of pulmonary tuberculosis using respiratory specimens, NPOC-NAAT (MiniDock) had a summary sensitivity against culture of 85.4% (95% confidence interval (CI) 82.2 to 88.1). The corresponding summary specificity was 97.6% (95% CI 96.9 to 98.1) (5 studies, 3291 participants; moderate-certainty evidence). Most studies had a low risk of bias in all QUADAS-2 domains. However, we downgraded the certainty of evidence by one level due to applicability concerns, as most studies performed NPOC-NAATs in laboratories rather than in peripheral settings. If the summary point estimates for NPOC-NAATs are applied to a hypothetical cohort of 1000 people, where 100 of those presenting with symptoms have pulmonary tuberculosis, NPOC-NAATs will miss 15 people with tuberculosis and wrongly diagnose 22 people without tuberculosis as having tuberculosis. In people living with HIV, NPOC-NAAT had a summary sensitivity against culture of 79.2% (95% CI 68.7 to 86.9), with a summary specificity of 96.7% (95% CI 94.6 to 98.1) (5 studies, 506 participants; moderate-certainty evidence). Amongst people with smear-negative, culture-positive pulmonary tuberculosis, NPOC-NAAT summary sensitivity and specificity were 66.7% (95% CI 58.8 to 73.7) and 97.7% (95% CI 97.0 to 98.3), respectively (3 studies, 2241 participants). There were not enough studies to perform other preplanned analyses, such as NPOC-NAATs performance in people with a history of tuberculosis and in children. When compared to Xpert MTB/RIF Ultra, an LC-aNAAT, NPOC-NAATs had lower sensitivity (85.6% vs 93.1%; -7.54 percentage points, 95% CI -11.6 to -3.47) but similar specificity (97.6% vs 97.3%; 0.34 percentage points, 95% CI -1.16 to 1.84) for the detection of pulmonary tuberculosis (5 studies, 3199 participants; moderate-certainty evidence). When compared to sputum smear microscopy, NPOC-NAATs had a higher sensitivity (86.7% vs 64.7%; 22.0 percentage points, 95% CI 15.7 to 28.3) with lower specificity (97.7% vs 99.9%; -2.17 percentage points, 95% CI -2.85 to -1.48) for detection of pulmonary tuberculosis (3 studies, 2516 participants). AUTHORS' CONCLUSIONS: NPOC-NAATs (Pluslife Minidock) are sensitive and specific for the detection of pulmonary tuberculosis using respiratory specimens. NPOC-NAATs have lower sensitivity for the detection of pulmonary tuberculosis in people living with HIV and with smear-negative/culture-positive tuberculosis. Compared to Xpert MTB/RIF Ultra, NPOC-NAATs have a lower sensitivity but a similar specificity for the diagnosis of pulmonary tuberculosis. Strengths of this review include the approach to identifying relevant studies and the number of participants included. Notably, only MiniDock NPOC-NAAT met the WHO NPOC-NAAT class definition and study inclusion criteria. Some uncertainty remains regarding the applicability of the review findings, as most studies performed testing in central laboratories rather than peripheral near point-of-care settings. Only one study evaluated NPOC-NAATs for the diagnosis of pulmonary tuberculosis in children, none of whom were diagnosed with microbiologically-confirmed tuberculosis. NPOC-NAATs provide accurate results and can allow rapid initiation of treatment for pulmonary tuberculosis. FUNDING: The WHO supported this systematic review. REGISTRATION: Generic protocol available on PROSPERO (CRD420251123343).