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

Background: 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. Material and Methods: 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). Results: 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. Conclusion: 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.