Mycobacterium tuberculosis Detection in Diverse Clinical Specimens by GeneXpert MTB/RIF: A Large-Scale Retrospective...

Mycobacterium tuberculosis (MTB) infection poses a significant global health challenge, with conventional diagnostic methods like acid-fast smear and culture techniques exhibiting limitations in sensitivity and efficiency. This retrospective study examined 4098 clinical samples from China-Japan Friendship Hospital between March 2018 and March 2019, focusing on the diagnostic performance of GeneXpert MTB/RIF across different specimen types.

The study encompassed various sample types, including bronchoalveolar lavage fluid (BALF), sputum, lung tissues, hydrothorax, and others. All samples were performed via acid-fast-straining, GeneXpert MTB/RIF and culture.

GeneXpert MTB/RIF demonstrated superior sensitivity (81.46%) and specificity (98.98%) in respiratory specimens compared to tissues (62.50%) and hydrothorax (46.15%). Notably, in acid-fast-straining-negative samples, GeneXpert MTB/RIF showed sensitivity and specificity of 73.43% and 98.8%, respectively, and reduced false negatives of acid-fast staining. Furthermore, the study explored Cycler Threshold (CT) values, revealing associations with bacterial load and sample types.

The findings highlight the importance of considering sample types in MTB diagnosis and underscore the potential of GeneXpert MTB/RIF as a valuable diagnostic tool, especially in respiratory specimens, contributing to improved tuberculosis management strategies. Additionally, the study recommended direct GeneXpert MTB/RIF testing of hydrothorax samples instead of acid-fast staining, further enhancing diagnostic accuracy and efficiency.