Publication:

Diagnostic accuracy of sputum gene xpert MTB /RIF and stool gene xpert-ultra in children with pulmonary tuberculosis in a resource constraint country

Background Diagnosis of tuberculosis in children remains a challenge especially in resource limited settings. This study aimed to determine the diagnostic accuracy of sputum Gene Xpert MTB/RIF and stool Xpert-Ultra for the diagnosis of PTB.

Methods This retrospective study was conducted in paediatric pulmonology ward of Bangabandhu Sheikh Mujib Medical University from March 2022 to December 2023.Consecuative 85 children aged 0-14 years with presumptive pulmonary tuberculosis (PTB) who provided both sputum and stool sample for GeneXpert and Xpert-Ultra respectively were included in the study. Diagnosis of PTB was confirmed by clinical, radiological, bacteriological or molecular evidence and taken as reference.

Result A total 119 children were enrolled; 85 of whom complete microbiological examination. PTB was diagnosed in 25 children. Of these 18(18/25) children was found positive in stool Xpert -Ultra and 6 children were tested positive by sputum /GA Gene Xpert MTB/RIF. All 6 positive sputum/GA samples were also positive on stool testing. The rate of concordance between stool and sputum was moderate with a kappa value of 0.441 (p<0.001). Overall sputum GeneXpert and stool Gene Xpert-Ultra showed Sensitivity of 24% and 72%, specificity of 100% and 100%, positive predicted value of 100% and 100%, negative predicted value of 75.95% and 89.55% and accuracy of 77.65% and 91.76% respectively.

Conclusion Stool gene xpert-ultra and sputum Gene Xpert both tests are highly specific for diagnosis of PTB. But sensitivity of stool Xpert-Ultra is more than the sputum Gene Xpert.