Stool testing for pulmonary TB diagnosis in adults

BACKGROUND: Mycobacterium tuberculosis is acid-fast and able to survive in the gastrointestinal tract. Thus, bacteria can be found in stool if sputum is swallowed. In this study, the accuracy of different diagnostic stool methods (microscopy, polymerase chain reaction PCR and culture) among adults with pulmonary TB (PTB) were assessed and compared with sputum culture.

METHODS: Embase and PubMed were searched to identify studies with data on stool testing among patients with clinically presumed or microbiologically verified PTB.

RESULTS: Thirteen relevant studies were included. A pooled sensitivity of one or more of the three TB identifying methods was 79.1% (95% CI 61.5–92.5). The sensitivity of stool microscopy, PCR and culture was respectively 41.1% (95%CI 24.9–58.2), 89.7% (95% CI 81.4–95.9) and 38.0% (95% CI 26.2–50.6). The heterogeneity of the studies included was high.

CONCLUSION: Our review findings indicate that the analysis of stool specimens as part of PTB diagnostics is useful. PCR methods were particularly helpful in detecting a substantial proportion of patients with PTB.