A seven-year prospective study on spondylodiscitis: epidemiological and microbiological features.

BACKGROUND

The aim of this paper was to enlarge the available knowledge on clinical and etiological aspects of patients affected by spondylodiscitis.

PATIENTS AND METHODS

All patients with spondylodiscitis admitted between January 2001 and December 2007 at the 1,300-bed University Hospital "Policlinico Umberto I" of Rome, Italy, were followed. Demographic characteristics, underlying diseases, invasive procedures, imaging studies, isolated microorganisms, treatment, complications, and outcome were recorded.

RESULTS

Eighty-one patients of mean age 57.7 +/- 14.7 years with lumbosacral (72.8%), thoracic (14.8%), and cervical tract (12.3%) site of infection were included, of which 38 developed community-acquired (CA) spondylodiscitis and 43 developed hospital-acquired (HA) spondylodiscitis. Underlying disease was present in 49.4% of patients. HA spondylodiscitis was diagnosed earlier (46.8 +/- 49.7 days) than CA spondylodiscitis (65.0 +/- 55.4 days) (P < 0.05). The most frequently isolated microorganisms were Staphylococcus aureus (28 strains, 43.1%), coagulase-negative staphylococci (CNS) (eight strains, 12.3%), Pseudomonas aeruginosa (eight strains, 12.3%), and three methicillin-resistant S. aureus (MRSA) strains were isolated in CA spondylodiscitis. Fungi and yeasts, isolated in six patients, represented 9.2% of all strains but 17.6% when considering only HA spondylodiscitis. Over 85% of patients were managed by conservative treatment alone, and the treatment time depended on clinical and laboratory evidence. Poor outcome was recorded in 12 (14.8%) patients, and was associated with neurological deficit symptoms (relative risk [RR] 2.87; 95% confidence interval [CI] 1.02-8.07; P < 0.05) and the time between diagnosis and the onset of symptoms > or = 60 days (RR 2.65; 95% CI 0.92-7.59; P < 0.05).

CONCLUSIONS

Infectious spondylodiscitis affects most frequently the elderly population, who are more exposed to healthcare contacts. Consequently, the infection etiology includes a growing proportion of multi-resistant bacteria and fungi.