Nosocomial and community-acquired meticillin-resistant Staphylococcus aureus infections in hospitalized patients (Spain, 1993-2003)

A series of annual surveys on the prevalence of infections in hospitalized patients in Spain was undertaken from 1993 to 2003 to describe clinical and demographic characteristics, trends and geographical variations in the proportion of meticillin-resistant Staphylococcus aureus (MRSA). A total of 8312 S. aureus infections in patients from 296 acute care hospitals pertaining to 17 regions in Spain were observed during the study period. Overall, 23.8% of these organisms were reported as meticillin resistant. The proportion of MRSA varied widely across regions and during the study period. Patients with nosocomial infections (NIs) had a two-fold higher prevalence of MRSA (31%) than patients with community-acquired infections (CAIs) (14%; P < 0.001). Nevertheless, there was an increasing trend in the prevalence of MRSA isolates, both in patients with NI (from 22% to 41%; P < 0.001) and with CAI (from 7% to 28%; P < 0.001) throughout the 11-year period. Geographical variations over the last three years (2001-2003) show a centripetal gradient, with the lowest MRSA prevalence in south-west Spain and the highest MRSA prevalence in the central regions. Almost five-fold differences in MRSA proportions were seen between regions (range 10.3-54.5%). Compared with bloodstream infections, infections in other sites were more likely to be caused by MRSA (adjusted odds ratios for surgical site, urinary tract, skin and respiratory infections of 1.2, 1.2, 1.5 and 2.1, respectively).