1226. Can Universal Decolonization Obviate the Need for Screening and Contact Precautions for Carriers of Methicillin-Resistant Staphylococcus aureus in a Medical Intensive Care Unit With MRSA Endemicity? An Interrupted Time Series Study

Abstract Background Universal decolonization of patients in intensive care units (ICUs) has been identified to be an effective infection control strategy of methicillin-resistant Staphylococcus aureus (MRSA). However, it remains uncertain whether universal decolonization can obviate the need for active surveillance testing (AST) and contact precautions (CPs) for MRSA carriers. Methods We conducted an interrupted time series study to evaluate whether universal decolonization (daily chlorhexidine bathing plus twice-daily intranasal mupirocin ointment for 5 days) without AST and CPs did affect the incidence of MRSA acquisition on clinical specimen and MRSA bacteremia (the first positive blood culture obtained more than 48 hours after ICU admission) in a medical ICU. There was a 12-month control period of universal decolonization combined with AST and CPs, followed by a 12-month intervention period of universal decolonization without AST and CPs for MRSA carriers. Changes in incidence density (new cases of MRSA acquisition on clinical specimen per 1,000 eligible patient-days) of MRSA were evaluated by segmented Poisson regression, and the cox proportional-hazards regression model was used to compare the differences in incidence of MRSA bacteremia between the two periods. Results The median overall prevalence of MRSA did not differ between the two periods (25.3% vs. 23.4%, P = 0.55), and the segmented Poisson regression analysis revealed that there were no significant differences in both level and trend of MRSA prevalence (P = 0.43 and P = 0.27, respectively). The incidence density of MRSA acquisition on clinical specimen was lower during the intervention period (5.7 vs. 4.5, P = 0.039). However, both level and trend of MRSA incidence density did not differ significantly whether to perform active surveillance and contact precaution or not (P = 0.94 and P = 0.81, respectively). No patient developed MRSA bacteremia during the control period and there were only two patients of MRSA bacteremia during the intervention period, which showed no significant difference (Log rank test, P = 0.21). Conclusion Universal decolonization without AST and CPs for MRSA carriers do not increase the incidence of MRSA acquisition on clinical specimen and ICU-attributable MRSA bacteremia in ICU with high prevalence rate of MRSA. Disclosures All authors: No reported disclosures.