Epidemiology and outcome of methicillin-resistant Staphylococcus aureus health-care associated pneumonia

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of healthcare-associated pneumonia (HCAP). HCAP confers high morbidity and mortality. In this study, we evaluated risk factors and clinical outomes of MRSA-HCAP. Methods: Between 08/2008 and 09/2010 we conducted a retrospective, singlecenter study. Seven hundred and eighty three patients with MRSA isolated from respiratory cultures were screened. The primary outcome was 28-day mortality. Results were computed using univariate and multiple logistic regression analysis. Results: The analysis included 63 patients (54.78%) with MRSA HCAP. The mean age (±SD) was 65.95 ± 15.4 years. Thirty seven (58.7%) were males. Fifty six (88.9%) had at least one associated comorbid medical condition. Forty two (66.7%) were treated with vancomycin, 4 (6.3%) with linezolid and the remaining 17 (27%) were switched between the two antimicrobials. Mean APACHE II (±SD) score was 18.8 (±7.3). Mortality rate was 28.6%. APACHE-II score, chronic obstructive pulmonary disease (COPD) and superinfection were found to be independent risk factors for 28-day mortality. Conclusions: MRSA is a significant etiology of HCAP which is more prevalent in the elderly. The associated mortality rate could be high and driven by several factors including APACHE II score and preexisting COPD.