Work

Diagnostic accuracy of stool Xpert MTB/RIF assay for adult pulmonary tuberculosis: a systematic review and meta-analysis

Year: 2026

Type: review

Study designs: Systematic Review, Meta-Analysis

Abstract: BACKGROUND: The etiological diagnosis of adult pulmonary tuberculosis (PTB) mainly relies on sputum or other respiratory specimens. However, some suspected patients cannot provide adequate sputum, limiting conventional diagnostic methods. Stool is an easily obtainable, non-invasive specimen and, combined with nucleic acid amplification techniques, may offer a new adjunct approach for rapid PTB diagnosis. OBJECTIVE: To systematically evaluate the diagnostic accuracy of stool Xpert MTB/RIF for adult PTB. METHODS: PubMed, Web of Science, Embase, and the Cochrane Library were searched through April 20, 2026. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. A random-effects model was applied to pool diagnostic accuracy estimates, evaluating stool Xpert against microbiological reference standards, including mycobacterial culture or Xpert testing on conventional specimens. RESULTS: Thirteen studies involving 3,033 adult patients were included. Stool processing and testing procedures varied considerably across studies, particularly in reagent types and pre-treatment steps such as homogenization and filtration. Against microbiological reference standards, pooled sensitivity and specificity were 84% (95% CI: 77%-89%) and 96% (95% CI: 90%-99%), respectively. Sensitivity was 84% in both people living with HIV(PLHIV) and uninfected populations, whereas specificity was higher in uninfected individuals (99%, 95% CI: 89%-100%) than in PLHIV patients (91%, 95% CI: 78%-97%). Significant heterogeneity was observed. Meta-regression by region and reference standard showed significant sensitivity differences between African and Asian studies and between studies using sputum culture versus other reference standards, suggesting potential sources of heterogeneity. Against a composite clinical reference standard, pooled sensitivity and specificity were 59% (95% CI: 43%-74%) and 100% (95% CI: 94%-100%), respectively. CONCLUSION: Stool Xpert MTB/RIF demonstrates high specificity and good sensitivity for diagnosing adult PTB, with comparable sensitivity in PLHIV and uninfected populations. Its non-invasive and convenient nature supports its potential as a rapid adjunct diagnostic tool. However, sensitivity may be influenced by region, sample processing methods, and choice of reference standard. Further standardized prospective studies are needed to define its clinical utility and clarify its role in clinical practice.

Source: BMC Infectious Diseases

DOI: 10.1186/s12879-026-14003-0