Abstract:

Objective: This study aimed to compare the diagnostic performance of three sputum-based Mycobacterium tuberculosis detection methods:traditional acid-fast staining, the BACTEC MGIT 960 rapid liquid culture system, and Xpert MTB/RIF, as well as their combined application in diagnosing pulmonary tuberculosis in comprehensive hospitals. Methods: The study included clinical data of 652 pulmonary tuberculosis patients and 166 non-tuberculosis patients treated at Kunshan First People’s Hospital between January 2021 and June 2023. Data included sputum specimen testing results (acid-fast staining, rapid culture, and GeneXpert MTB/RIF) and clinical diagnostic information. Results: Acid-fast staining showed a sensitivity of 28.8% (188/652), specificity of 98.8% (164/166), positive predictive value (PPV) of 98.9% (188/190), negative predictive value (NPV) of 26.1% (164/628), and a Kappa value of 0.136 (95%CI: 0.109-0.163). BACTEC MGIT 960 rapid culture showed a sensitivity of 39.3% (256/652), specificity of 98.2% (163/166), PPV of 98.8% (256/259), NPV of 29.2% (163/559), and a Kappa value of 0.199 (95%CI: 0.164-0.234). GeneXpert MTB/RIF showed a sensitivity of 44.5% (290/652), specificity of 99.4% (165/166), PPV of 99.7% (290/291), NPV of 31.3% (165/527), and a Kappa value of 0.242 (95%CI: 0.204-0.281). Combination of the 3 methods achieved a sensitivity of 53.8% (351/652), specificity of 97.6% (162/166), PPV of 98.9% (351/355), NPV of 35.0% (162/463), and a Kappa value of 0.309 (95%CI: 0.263-0.354). Conclusion: Compared to individual detection methods, the integrated approach combining three testing methods can improve efficacy and accuracy of pulmonary tuberculosis diagnosis, providing important guidance for tuberculosis detection in comprehensive hospitals.

Key words: Mycobacterium tuberculosis, Staining and labeling, Culture techniques, Molecular diagnostic techniques