Detection of Mycobacterium tuberculosis in Buccal Swab Specimens in Children with Pulmonary Tuberculosis Using Cartridge-based Nucleic Acid Amplification Test

The study was designed to detect Mycobacterium tuberculosis (M.tb) in buccal swab specimens using cartridge-based nucleic acid amplification test (CBNAAT) in children suffering from pulmonary tuberculosis (TB) and to compare with CBNAAT results with gastric aspirate (GA) and sputum specimen. Materials and methods: This observational study included children 15 years of age attending Department of Pediatrics of a tertiary care hospital diagnosed as presumptive pulmonary TB. Gastric aspirate/induced sputum (IS) sample and buccal swab were collected from all the study subjects and subjected to CBNAAT. Acid-fast bacilli (AFB) microscopy was also performed on GA/IS samples. Results: Fifty presumptive cases of pulmonary TB were enrolled in the study. Fifteen (30%) buccal swab samples and 41 (82%) GA/IS samples were positive for CBNAAT. Gastric aspirate was positive in 23/24 (98%) subjects which was significantly higher as compared to buccal swab results (p = 0.0001). Induced sputum was positive in 18/26 (69.2%) samples which was comparable to buccal swab results (p < 0.092). AFB microscopy was positive in only 10 (5%) subjects. Rifampicin resistance was demonstrated in 9 (18%) subjects on GA/IS and 4 (8%) cases on buccal swab detected by CBNAAT. Conclusion: Buccal swabs can be used to detect M.tb in children with pulmonary TB. The results were statistically comparable to IS but inferior to GA specimen. It can serve as simple and convenient alternative method.