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

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.

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.

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.

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.