Active surveillance culturing impacts methicillin-resistant Staphylococcus aureus acquisition in a pediatric intensive care unit*

Abstract

To determine whether active surveillance culturing for methicillin-resistant Staphylococcus aureus (MRSA) decreases nosocomial MRSA acquisition in the pediatric intensive care unit. Before and after observational study. A tertiary care, 20-bed, pediatric intensive care unit. All patients admitted to the pediatric intensive care unit. Anterior nares cultures for MRSA were obtained on admission and weekly in the pediatric intensive care unit from January 2007 to December 2009 as part of a hospital quality improvement project. MRSA admission prevalence and nosocomial incidence density were determined retrospectively for 2006 and prospectively for 2007-2009. Nosocomial MRSA incidence density during the intervention period was determined monthly and analyzed by trend analysis by using a general linear model. The correlation of active surveillance culturing compliance with nosocomial acquisition of MRSA was analyzed. Possible confounding by healthcare worker hand hygiene compliance observed during the intervention period was also analyzed by multivariate linear regression analysis. The yearly MRSA incidence density significantly decreased from 2006 to 2009 (6.88 per 1,000 patient days to 1.45 per 1,000 patient days, p < .001) and from 2007 to 2009 (7.32 per 1,000 patient days to 1.45 per 1,000 patient days, p < .001). Trend analysis demonstrated a significant decline in MRSA acquisition over time following the introduction of active surveillance culturing (p < .001). Surveillance culturing was significantly associated with the decline in MRSA acquisition observed in the pediatric intensive care unit by multivariate regression analysis when controlling for hand hygiene (p = .01). Active surveillance culturing resulted in significantly decreased nosocomial acquisition of MRSA in a pediatric intensive care unit setting. Admission and weekly active surveillance culturing appears to be an effective tool to decrease the spread of MRSA in the pediatric intensive care unit, independent of improvement in hand hygiene compliance. The impact on hospital-acquired MRSA infections and the cost benefit of active surveillance culturing require further study.