One- versus two-specimen Xpert strategy to discontinue airborne isolation in suspected pulmonary tuberculosis: systematic review and meta-analysis.

Background: Evaluation of a patient with suspected pulmonary tuberculosis (TB) involves initiation of airborne infection isolation (AII). However, guidelines detailing discontinuation of AII utilizing the Xpert MTB/RIF provide little clarity between use of one-specimen (1-Xpert') versus two-specimens (2-Xpert').
Objectives: To evaluate the diagnostic accuracy of one-Xpert versus two-Xpert strategy in guiding discontinuation of AII.
Methods: Data sources: PubMed, Embase, and EBSCO databases.
Study Eligibility Criteria: Studies providing diagnostic accuracy data for one- versus two-Xperts in discontinuation of AII.
Participants: Adult patients with suspected TB.
Tests: Xpert MTB/RIF on one- versus two-sputum specimens. Reference standard: Solid and liquid culture media. Assessment of risk of bias: Quality Assessment of Diagnostic Accuracy Studies tool was used. Methods of data synthesis: Meta-analysis was performed to calculate the pooled sensitivities and specificities using Stata 17.2.
Results: Four studies were included involving 1776 patients. A total of 68% were males, 36% were HIV positive, and 80% participants belonged to the United States. In patients with suspected pulmonary TB, 7% (95% CI, 6-9%) participants were found to have culture-positive MTB. For one-Xpert strategy, the pooled sensitivity was 86% (95% CI, 75-92%; I ² , 1.05%) and specificity was 100% (95% CI, 99-100%; I ² , 36%). Two-Xpert strategy had a pooled sensitivity of 92% (95% CI, 84-96%; I ² , 16%) and a specificity of 100% (95% CI, 98-100%; I ² , 27%). There was statistically significant difference between sensitivities of one-Xpert and two-Xpert strategies (p 0.05) with no statistically significant difference in their specificities.
Discussion: The results of this review must be interpreted in the context of a predominantly low-TB prevalence setting. Two-Xpert strategy has an incrementally higher sensitivity when compared with one-Xpert strategy with similar specificities between the two. Obtaining a second Xpert is crucial for individuals with a continued high suspicion for TB or those at a high risk of morbidity/mortality from TB.
(Copyright © 2023 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)