# P-1395. Comparative Analysis of Sensitivity and Add-On Value of Xpert and Xpert Ultra in Diagnosing Pulmonary Tuberculosis and Stool Samples of Children in Indian

## TL;DR

This study compares Xpert and Xpert Ultra tests for diagnosing tuberculosis in children using pulmonary and stool samples, finding that stool samples can be a useful addition when respiratory samples are hard to collect.

## Contribution

The study evaluates the add-on value of stool samples alongside pulmonary samples for diagnosing TB in children using Xpert and Xpert Ultra.

## Key findings

- Xpert Ultra showed higher detection rates in both pulmonary and stool samples compared to Xpert.
- Stool samples demonstrated good sensitivity but limited specificity for TB diagnosis.
- Stool samples could serve as an additional diagnostic tool when respiratory samples are difficult to obtain.

## Abstract

Microbiological confirmation of tuberculosis (TB) among most children is challenging due to the paucibacillary nature of the disease and difficulty in appropriate specimen collection. Thus, This study aimed, first, to compare the sensitivity and specificity of Xpert and Xpert Ultra with Gold Standard (MGIT); second, to compare the add-on value of stool Xpart and Xpart Ultra samples with regular age based Pulmonary sample (Sputum/Induced sputum (IS)/GA/GL).

This study was conducted by the National Institute of TB and Respiratory Diseases, New Delhi, from July 2022 to July 2023, using 200 presumptive pulmonary TB children attending OPD/Children Ward. From each recruited patient, pulmonary and stool samples were collected in a sterile container. Bivariate analyses were performed to calculate the sensitivity and specificity of Xpert and Xpert Ultra with Gold Standard (MGIT) for pulmonary and stool samples using Stata.

The results revealed that in the pulmonary sample, the detection rate for Xpert was 45.3% and 54.7% for Xpert Ultra, while in the stool sample, the detection rate for Xpert was 46.9% and 57.2% for Xpert Ultra. The sensitivity of Xpert in pulmonary and stool samples was 98.2% and 84.2%, while for Xpert Ultra, it was 100.0% and 96.5%, respectively. Similarly, the specificity of pulmonary and stool samples for Xpert was 82.1% and 41.8%, while for Xpert Ultra, it was 39.5% and 54.4%, respectively.

: Overall, both Xpert and Xpert Ultra testing on stool samples showed good sensitivity and limited specificity in diagnosing Mycobacterium TB in children. The findings highlighted that stool may be considered an additional specimen to support the diagnosis of TB in pediatric cases, especially in settings where it is difficult to get respiratory samples. Further studies should be considered its importance as a diagnostic tool. Thus, effective interventions are needed for awareness creation, increased capacity building, and active case finding to overall enhance the performance of the TB test.

All Authors: No reported disclosures