Diagnostic Role of Cartridge-Based Nucleic Acid Amplification Test (CB-NAAT) in Both Pulmonary and Extra-Pulmonary Pediatric Tuberculosis: A Hospital-Based Study

Background: Early diagnosis of pediatric tuberculosis (TB) still remains a challenge due to the paucibacillary nature of the disease. Objectives: To assess the role of CB-NAAT in diagnosing pulmonary and extrapulmonary tuberculosis as compared to AFB smear and Mycobacterium tuberculosis culture in clinically diagnosed pediatric tuberculosis cases. Study design: Hospital-based prospective study. Methods: A total of142 patients with strong clinical suspicion of pulmonary or extra-pulmonary tuberculosis were enrolled over a period of two years and then results of CB-NAAT were compared to conventional methods (culture/ AFB smear) on follow-up. Results: In subjects who had clinically diagnosed tuberculosis, culture was positive in 18.9% of cases, AFB smear was positive in only 12.1% whereas CB-NAAT was positive in 55.4% of subjects. The sensitivity, specificity, PPV, and NPV of CB-NAAT in patients with culture proven tuberculosis were100%, 83.3%, 47.5%, and 100% respectively with a diagnostic accuracy of 93.3%. and 60%, 100%, 100%, and 65.8% respectively with a diagnostic accuracy of 80.2% in clinically diagnosed pulmonary cases. Conclusion: CB-NAAT has true diagnostic potential with good sensitivity in confirmed cases and significantly better sensitivity than conventional methods in clinically diagnosed cases.