Comparative Analysis Of Stool As An Alternative Sample In The Diagnosis Of Pulmonary Tuberculosis Among Adults And Children In Ogbomosho, Nigeria

Abstract

Background/Purpose: Tuberculosis (TB) is an infectious bacterial disease caused by Mycobacterium tuberculosis (MTB). It is a matter of serious public health concern in lower-income and lower-middle-income countries.

Methods: In this study, a comparative analysis of stool samples from 101 adult (91 pre-confirmed pulmonary TB patients, 10 sputum negative patients) and 99 children (presumptive TB patients). Their stool samples were collected, processed and analyzed using Xpert MTB/RIF Ultra technique and AFB microscopy.

Results: While using Xpert MTB/RIF Ultra assay as our “reference standard”, a sensitivity of 96 %, Specificity of 83%, Positive Predictive Value (PPV) of 87 %, and Negative Predictive Value (NNP) of 87 % was observed with stool Xpert MTB/RIF Ultra technique. Also, Ziehl Neelsen’s Stain Microscopy has a Sensitivity of 64%, Specificity of 12%, PPV of 80% and NNP of 20% while Fluorescence Stain Microscopy reveal a Sensitivity of 94 %, Specificity of 20 %, PPV of 80 %, and NNP of 20 % in stool sample.

Conclusion: This study has elucidated Xpert MTB/RIF Ultra assay in stool samples provide an alternative option to sputum in the diagnosis of pulmonary tuberculosis with high level of diagnostic accuracy and precision. Furthermore, Fluorescence Stain Microscopy has shown to be more sensitive and specific than Ziehl Neelsen’s stain Microscopy.