A comprehensive updated Cochrane review evaluated the diagnostic performance of low-complexity automated nucleic acid amplification tests (LC-aNAATs) for extrapulmonary tuberculosis across 37 studies, most of which assessed Xpert Ultra. The findings show that Xpert Ultra demonstrates high sensitivity for tuberculous meningitis, reaching 88%, and high specificity across most specimen types, indicating strong reliability for ruling in disease when positive. Sensitivity varied by specimen—moderate for pleural fluid and lymph node samples—while rifampicin resistance detection with Xpert Ultra showed near-perfect accuracy with a sensitivity of 100% and specificity of 99%.
Results for Truenat MTB Plus were reported descriptively due to insufficient data for pooled analysis, but available studies demonstrated generally high sensitivity across cerebrospinal fluid and lymph node aspirates. The review concludes that LC-aNAATs are valuable tools for diagnosing extrapulmonary tuberculosis, although performance differs by specimen type and data gaps remain for several technologies. The authors emphasize the need for improved reference standards for paucibacillary samples and additional validation of emerging LC-aNAAT platforms to strengthen diagnostic certainty in diverse clinical settings.