Diagnostic Accuracy of Cartridge Based Nucleic Acid Amplification Test (CBNAAT) in Stool Samples in Pediatric Tuberculosis.

Objectives: To find out the diagnostic accuracy of stool Cartridge-based nucleic acid amplification test (CBNAAT) as an alternate method as compared to CBNAAT in gastric aspirate (GA) samples in pediatric tuberculosis (TB).
Methods: This cross-sectional study was performed at Department of Pediatrics of a tertiary care hospital. Children aged 0-18 y diagnosed as presumptive tuberculosis were consecutively enrolled. Gastric aspirate and corresponding stool sample was subjected to CBNAAT and its performance was compared in both samples using appropriate statistical tests.
Results: Total 100 patients were enrolled in the study. Diagnostic accuracy of CBNAAT was 81% and 80% in gastric aspirate and stool sample respectively. On comparing gastric aspirate with corresponding stool sample there was 97% agreement, with Cohen's kappa value of 0.94. There was a statistically significant association observed between gastric aspirate CBNAAT and stool CBNAAT p <0.001 using chi square test. Sensitivity of gastric aspirate CBNAAT and stool CBNAAT was 75% and 73% respectively and specificity was 100% for both the samples compared against Composite Reference Standard (CRS).
Conclusions: The diagnostic accuracy of stool CBNAAT is comparable to GA CBNAAT in children and can be used as a good alternative to gastric aspirate for diagnosis of pulmonary and disseminated tuberculosis in children.
(© 2023. The Author(s), under exclusive licence to Dr. K C Chaudhuri Foundation.)