Stool Gene-Xpert MTB/Rif test for the diagnosis of childhood pulmonary tuberculosis.

Abstract

Diagnosing childhood pulmonary tuberculosis (PTB) is challenging due to nonspecific symptoms and difficulties in obtaining respiratory specimens. This study evaluates the diagnostic performance of the stool-based Xpert MTB/RIF assay as a noninvasive alternative compared to respiratory specimens in suspected cases. This prospective, hospital-based study was carried out at a tertiary care centre, from November 2022 to October 2024. A total of 244 pediatric patients under 15 years of age with suspected PTB were included. Both stool and respiratory samples were collected and analyzed using the Xpert MTB/RIF assay and Mycobacteria growth indicator tube (MGIT) culture. Data analysis was performed using IBM SPSS software (version 22). The Xpert MTB/RIF assay detected <i>Mycobacterium tuberculosis</i> in 10.2% of respiratory specimens and 6.1% of stool samples, while MGIT culture identified it in 8.6% of respiratory specimens and 5.3% of stool samples. Detection rates were higher in respiratory specimens. Stool-based diagnostics showed comparable performance, with reported sensitivities of 32% to 83.3% in prior studies. Baseline characteristics showed a mean patient age of 7.19 years, with 59.02% males. Fever (74.18%) and cough (52.8%) were the most common clinical features. The stool Xpert MTB/RIF assay is a promising diagnostic tool for PTB in children, especially in resource-limited settings where respiratory sample collection is difficult. Although its sensitivity is lower compared to respiratory specimens, its high specificity makes it a reliable alternative. Future research should optimize stool sample processing and explore advanced diagnostic assays to improve sensitivity and accuracy.