Smaller studies indicate that the incidence of pyogenic spondylodiscitis is increasing, possible related to a growing elderly population. Data supporting this is sparse, and we therefore studied patient characteristics and changes in spondylodiscitis incidence 1995–2008.

In a population-based study we identified all patients aged ≥18 years treated for pyogenic spondylodiscitis in Funen County, Denmark (population 483 123). Annual incidences were determined. Demographics, symptoms and diagnostic methods were recorded.

We found 192 cases: median age 66.6 years; 57.3% men; 76.6% culture positive cases. Staphylococcus aureus was the most common pathogen (55.1%). During 1995–2008 the overall incidence, incidence of culture negative cases, and incidence of cases due to S. aureus increased 2.2–5.8, 0.3–1.8, and 1.6–2.5 cases per 100 000 person years, respectively. The elderly had the highest incidence compared to those aged ≤70 years (rate ratio for men 5.9 (95% CI: 4.2–8.5) and for women 3.5 (95% CI: 2.3–5.3)).

During 1995–2008 the overall incidence of S. aureus and culture negative cases of spondylodiscitis increased and remained highest among the elderly. Whether the increase is real or is a result of improved diagnostic methods and workup remains unknown.

Summary: In a population-based study describing the characteristics of patients with pyogenic spondylodiscitis and the changes in incidence during 1995–2008, we found that the overall incidence increased considerably and that the disease was the most common among the elderly.