Comparative analysis of pathogen detection methods in spinal infections: a retrospective study of 287 cases

PURPOSE: This study aims to systematically evaluate the efficacy and timeliness of various specimens and diagnostic methods used to identify pathogens in spinal infections, thereby informing clinical diagnostic pathways. METHOD: We conducted a retrospective examination of patients diagnosed with spinal infections between January 2023 and January 2025. We compared positivity rates and time-to-detection for microbial culture, mNGS, qPCR and RBT/SAT across different types of specimens: blood, muscle/vertebral biopsy, intraoperative specimens, and postoperative drainage. RESULTS: Among 287 patients, 213 had confirmed pathogens: non-specific bacteria (42.0%), Mycobacterium tuberculosis (34.7%), and Brucella spp. (21.1%). The overall positivity rate for mNGS was 83.0%; for brucellosis serology (RBT/SAT), the median time to result was 2.0 days. For M. tuberculosis, mNGS yielded a positivity rate of 81.8%. For Brucella, RBT/SAT showed a sensitivity of 91.2% and a median detection time of 3 days. For non-specific bacteria, culture, mNGS, and qPCR performed comparably. The type of specimen significantly influenced the outcomes: blood cultures were relatively rapid but exhibited lower yields (35.7%); ultrasound-guided muscle abscess aspirates demonstrated favorable yield and speed across methods. CONCLUSION: mNGS offers high sensitivity and rapidity; however, traditional culture and qPCR remain vital. Blood and muscle abscess aspirates are useful for rapid diagnosis. Implementing a systematic diagnostic workflow can enhance both the accuracy and timeliness of managing spinal infections.