Epidemiology and predictors of multidrug-resistant community-acquired and health care-associated pneumonia

There are limited U.S. data describing the risk factors for multidrug-resistant organism (MDRO) isolation in community-acquired pneumonia (CAP) and health care-associated pneumonia (HCAP). However, concern for the presence of these pathogens drives the prescribing of empiric broad-spectrum antibiotics for CAP and HCAP. A retrospective study of all adults hospitalized with community-onset pneumonia (CAP and HCAP) at a large U.S. medical center from January 2010 to December 2011 was conducted. The objective was to ascertain the rate of pneumonia caused by MDROs and to evaluate whether HCAP is a risk factor for MDRO pneumonia. Univariate and propensity score-adjusted multivariate analyses were performed. A total of 521 patients (50.5% CAP and 49.5% HCAP) were included. The most common etiologies of pneumonia were primary viral and Streptococcus pneumoniae. MDROs were isolated in 20 (3.8%) patients overall, and MDROs occurred in 5.9% and 1.9% of HCAP and CAP patients, respectively. The presence of an MDRO was not associated with HCAP classification (odds ratio [OR]=1.95; 95% confidence interval [95% CI], 0.66 to 5.80; P=0.23) or with most of its individual components (hemodialysis, home infusion, home wound care, and ≥48-h hospitalization in the last 90 days). Independent predictors of MDRO included the following: Pseudomonas aeruginosa colonization/infection in the previous year (OR=7.43; 95% CI, 2.24 to 24.61; P