INFECTIVE SPONDYLODISCITIS – DOES A PATHOGEN MAKE A DIFFERENCE?

Abstract

In the recent years the number of patients treated for infective spondylodiscitis at our institution increases steadily. In a previous analysis it was demonstrated that Staphylococcus aureus was the most frequent pathogen causing this infection. The aim of the present study was to evaluate whether infection with this pathogen carries also a worse prognosis.

Case records of patients treated for spondylodiscitis at the Department of Infectious Diseases, Ljubljana in the years 1990 – 2006 were reviewed. The following data were recorded: age, sex, clinical features, causative agents, underlying disease, previous or concomitant infections, previous operations, results of x-ray and other diagnostic examinations, complications and outcome of the disease. The data were analysed using EpiInfo 6.

One hundred twenty six patients (78 males, 48 females) with infective spondylodiscitis were analysed in this study. The mean age was 61.6 years (range: 20 – 95 years). In 97 (77%) patients the causative pathogen was demonstrated. S. aureus was the most frequent pathogen isolated in 66 (52.4%) out of all the patients and in 65% of all microbiologically documented infections. Only two isolates were methicillin-resistant. Staphylococcal infection was significantly more frequent in male than in female patients (P = 0.04). There were no significant differences in age, underlying diseases, previous operations and other risk factors between patients with staphylococcal and non-staphylococcal spondylodiscitis, although patients with non-staphylococcal infections were more likely to have a previous infection during the six months before the beginning of their illness. Case-fatality rate was 9.5%, 12 patients died. There was no difference in mortality between the two groups, but patients with staphylococcal infections had significantly more complications such as epidural or paravertebral abscesses (P < 0.002) and were also more frequently operated on (P = 0.02). The duration of treatment and hospitalisation did not differ significantly between those two groups. In 9/128 (7.3%) patients, infective endocarditis was also found.

S. aureus remains an important pathogen causing spondylodiscitis. Mortality in recent years has decreased significantly at our institution but our results show that patients with staphylococcal spondylodiscitis tend to have a more severe course of the disease and are more often in need of surgical intervention.