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Background: Rapid and accurate diagnosis of childhood tuberculosis (TB) is challenging because children are often unable to produce the sputum sample required for conventional tests. Stool is an alternative sample type that is easy to collect from children, and studies investigating the use of stool for molecular detection of Mycobacterium tuberculosis (Mtb) have led to promising results. Our objective was to evaluate stool as an alternative specimen to sputum for Mtb detection in children. We did so using the TruTip workstation (Akonni Biosystems), a novel automated lysis and extraction platform.Methods: We tested stool samples from 259 children aged 0-14 years old, in Lima, Peru who presented with TB symptoms. Following extraction with TruTip, we detected the presence of Mtb DNA by IS6110 real-time PCR. We calculated assay sensitivity in two groups: (1) children with culture confirmed TB (N = 22); and (2) children with clinically-diagnosed unconfirmed TB (N = 84). We calculated specificity among children in whom TB was ruled out (N = 153). Among children who were diagnosed with TB, we examined factors associated with a positive stool test.Results: Assay sensitivity was 59% (95% confidence interval [CI]: 39-80%) and 1.2% (95% CI: 0.0-6.5%) in children with culture-confirmed and clinically-diagnosed unconfirmed TB, respectively, and specificity was 97% (95% CI: 93-99%). The assay detected Mtb in stool of 7/7 children with smear-positive TB (100% sensitivity; 95% CI: 59-100%), and in 6/15 of children with smear-negative, culture-confirmed TB (40% sensitivity; 95% CI: 16-68%). Older age, smear positivity, culture positivity, ability to produce sputum and cavitary disease were associated with a positive stool result.Conclusion: Testing of stool samples with the TruTip workstation and IS6110 amplification yielded sensitivity and specificity estimates comparable to other tests such as Xpert. Future work should include detection of resistance using the TruTip closed amplification system and assay optimization to improve sensitivity in children with low bacillary loads. [ABSTRACT FROM AUTHOR]

Objective: Diagnostic testing for tuberculosis depends on microbiological detection of Mycobacterium tuberculosis (Mtb) in sputum. For patients unable to expectorate sputum, such as children and individuals living with HIV, this poses barriers to rapid diagnosis and treatment initiation. Therefore, this study aimed to use oral swabs as an alternative sample type for Mtb detection via molecular testing. Results: In a pilot study, we aimed to evaluate sensitivity of Mtb detection via oral swabs using Xpert MTB/RIF ULTRA. We enrolled 33 TB cases and 30 controls from Lima, Peru, and detected Mtb from oral swabs with a sensitivity of 45% (95% confidence interval (CI) 29–62%) and specificity of 100% (95% CI 89–100%) using liquid culture of sputum as reference test. Our current protocol will need optimization, but these results support future exploration of the use of oral swabs for Mtb detection. [ABSTRACT FROM AUTHOR]