Methicillin-Resistant Staphylococcus aureus central nervous system infections – Analysis and outcome

Abstract

Introduction. Methicillin-Resistant Staphylococcus aureus (MRSA)-associated infections are potentially devastating and fatal. It has two distinct pathogenic mechanisms: postoperative and spontaneous. In the study presented here, we review the epidemiology, clinical features, response to treatment, and outcome of MRSA central nervous system infections at our tertiary referral institute. Material and methods. In this analysis, we reviewed the medical records of all patients who were diagnosed with S. aureus meningitis between January 2010 and December 2012. Clinical information included predisposing factors, past medical history, comorbidities, mode of acquisition of infection, as well as therapeutic management, length of treatment, and clinical outcomes were analyzed. Results. A total of 34 cases of MRSA meningitis were diagnosed during the study period. There were 28 (82.4%) cases of postoperative meningitis and 6 (17.6%) cases of spontaneous meningitis. A majority (24/28) of the patients had one or the other predisposing conditions for the infection. Compared with patients with postoperative meningitis, patients with spontaneous meningitis had a significantly older (31.93 yrs vs 55.8 yrs; p = 0.021) and higher frequency of community-acquired infection (100% vs. 39%; p = 0.007). In patients with postoperative meningitis, the median postoperative day when the infection manifested clinically was day- 19 (range, 3–90 days). A total of 25/34 (74%) patients received definitive antibiotic (vancomycin and/or linezolid based) therapy. Nine patients were continued on empirical antimicrobial therapy (combination of ceftriaxone, amikacin, and metronidazole), as the organism was sensitive to those drugs. There were no in-hospital mortalities in our series, though 3/34 patients (8.8%) were discharged with Glasgow coma score (GCS)< 8 and 8/34 patients (23.5%) were discharged with GCS 9–12 from the hospital. Conclusion. In acute bacterial meningitis, there is a progressive shift from methicillin-sensitive strains to methicillin-resistant strains in recent years. Although most patients have a favorable response to vancomycin and linezolid, the beneficial effect of combined antimicrobial therapy or alternative antibiotics needs to be evaluated.