Age- and Site-Dependent Pathogens in Spondylodiscitis: A Study of 10,801 Cases

Pyogenic spondylodiscitis (PSD) is a life-threatening infection with increasing incidence in aging populations. This study investigates age- and localization-dependent shifts in the pathogen spectrum to provide an epidemiological basis for empiric antimicrobial therapy.

We conducted a retrospective analysis of German nationwide hospital discharge data from 2024 (InEK), including 10,801 PSD cases. Patients were stratified by age (<65, 65-79, and ≥80 years) and spinal localization (cervical, thoracic, lumbar, and multisegmental).

Overall in-hospital mortality was 7.1% (with an unadjusted weighted average of 6.4% across age-stratified subgroups). The prevalence of Staphylococcus spp. declined with increasing age (35.7% to 21.3%; p<0.001), whereas Enterococcus spp. (3.9% to 11.8%) and Enterobacterales (17.3% to 21.4%) increased (p<0.001). Lumbar infections showed a significantly higher prevalence of Enterobacterales (28% among pathogen-positive cases) and Enterococcus spp. (13% among pathogen-positive cases) compared to cervical sites (p<0.001).

In a large-scale nationwide cohort, pathogen distribution in PSD is moderately associated with patient age and spinal localization. While confirming previously described trends, these population-based findings reinforce that uniform empiric antimicrobial regimens may inadequately cover the risk profile in elderly patients with lumbar manifestations.