977Impact of Decolonization on Methicillin-resistant Staphylococcus aureus Transmission in Hospitalized Neonates

Background. MRSA is a leading cause of healthcare associated infections. Decolonizing hospitalized patients may eliminate a bacterial reservoir to reduce MRSA transmission and prevent infections. Our objective was to measure the association of colonization pressure with transmission in the neonatal intensive care unit (NICU) and to determine whether decolonization decreases MRSA transmission. Methods. Neonates admitted to our tertiary care NICU have weekly nares cultures to detect MRSA colonization. We identified neonates with a positive culture for MRSA between January 2007 and December 2013. Some neonates with a positive culture growing MRSA were decolonized with mupirocin. Hand hygiene compliance was monitored. Weekly colonization pressure was defined as the percentage of total patient-days in the preceding 7 days that were MRSA-colonized patient–days. The association of colonization pressure and decolonization with MRSA acquisition was estimated using negative binomial regression models to calculate incidence rate ratios (IRRs). Results: There were 4,746 neonates admitted in the NICU, accounting for 101,082 patient days. One hundred and one neonates who had positive cultures for MRSA accounted for 3,356 MRSA colonized patient-days; neonates who were decolonized accounted for 2,227 patient-days, while neonates who were not decolonized accounted for 1,129 patient-days. In unadjusted analysis, for every 1% increase in colonization pressure there was a 7% increase in the risk of MRSA acquisition (IRR 1.07, 95% CI 1.00, 1.14). After adjusting for decolonization and hand hygiene compliance, there was an increase in the incidence of MRSA associated with colonization pressure due to untreated colonized neonates (IRR 1.14, 95% CI 1.01, 1.28), but there was no increase in the incidence of MRSA associated with colonization pressure due to treated colonized neonates (IRR 1.01, 95% CI 0.92, 1.12). Compliance with hand hygiene was not associated with MRSA incidence (IRR 1.00, 95% CI 0.99, 1.02). Conclusion. Our results suggest that colonization pressure is associated with MRSA transmission, and decolonization may decrease colonization pressure and reduce MRSA transmission in the NICU. Disclosures. All authors: No reported disclosures.