Utility of stool- CBNAAT testing for the diagnosis of pulmonary tuberculosis in children

ABSTRACT: Objectives: Paediatric tuberculosis (TB) is among one of the major health issues with diagnostic challenges globally. Collecting respiratory sample for analysis is traumatic for kids. Therefore, non-respiratory samples are being studied as a non-invasive diagnostic method. This study focussed on evaluating cartridge-based nucleic acid amplification test (CBNAAT) using stool sample in clinically suspected cases of paediatric pulmonary tuberculosis (PTB) and analyzing its accuracy with that of gastric aspirates (GA)-CBNAAT. Materials and Methods: This single-centric cross-sectional study included 50 children aged 0.25-16 years, suspected as PTB. GA and stool sample were obtained from the enrolled patients and CBNAAT diagnosis was performed. Statistical analysis: Statistical analysis was done using Microsoft Excel and SPSS v23. Continuous variables are represented as mean±standard deviation and categorical data as percentages and frequency. Results: Out of 50 patients, 28 were microbiologically confirmed, 7 were clinically diagnosed as TB and 15 were diagnosed other than TB. All microbiologically confirmed cases were GA-CBNAAT positive, but only 18 patients were stool-CBNAAT positive. Both GA and stool CBNAAT had strong relation with high Cohen’s kappa value of 0.613 and highly acceptable significant value 0.0001. Stool-CBNAAT had sensitivity, specificity, PPV, NPV and diagnostic accuracy of 64.3%, 100%, 100%, 68.8%, and 80%, respectively as compared to GA-CBNAAT test. Conclusion: Stool-CBNAAT was found to have comparable accuracy with that of GA-CBNAAT. It can be considered as a feasible, reliable, and non-invasive diagnostic tool for PTB. Keywords: Cartridge-based nucleic acid amplification test, Pediatric tuberculosis, Pulmonary tuberculosis, Stool-CBNAAT, GA-CBNAAT, Diagnosis