2304. Decreased Incidence of Methicillin-Susceptible Staphylococcus aureus (MSSA) Infections after Implementation of Routine Surveillance and Decolonization in a Level IV Neonatal Intensive Care Unit (NICU)

Abstract

Background Staphylococcus aureus (SA) is a leading cause of hospital-acquired infection, including bloodstream infection (BSI), in NICUs. In this study, we evaluated the effect of screening and decolonization of MSSA-colonized babies with mupirocin on the rate of MSSA infection. Patients and Methods. Study design: Sequential time series. Pre-intervention period, January 2015–March 2017; wash out period, April 2017; intervention period, May 2017–March 2018. Population: Neonates admitted to a Level IV NICU with anticipated stay of greater than 2 days. Intervention: A single swab of the nares, umbilicus & groin was sent weekly for SA surveillance culture. MSSA-colonized neonates were decolonized with mupirocin application to nares, umbilicus and abraded skin twice daily for 5 days. Outcome measures: Comparison of rates of MSSA infections during pre- and post-intervention periods. Infections included BSI and skin/wound infections, excluding patients with MSSA from only eye or respiratory specimens. Comparators: Change in rates of Gram-negative and MRSA BSI. Change in rates of MSSA BSI in an affiliated NICU with the same medical staff but no intervention.ResultsMSSA BSI decreased from 0.37 per 1,000 hospital days (n = 15) to 0.00 (n = 0), P = 0.0092. All MSSA infections decreased from 0.62 (n = 25) to 0.11 (n = 2), P = 0.0078. Of 694 eligible neonates, 98.8% were screened at least once for MSSA colonization, which was detected in 92 (13.4%) infants. Median weekly prevalence of colonization was 6.7%. Median length of stay of neonates after initial detection of colonization was 30 days. Of colonized neonates, 92% received mupirocin treatment, with a median of 1 course of mupirocin treatment per patient (range, 1–7 courses). Of 54 isolates tested, all were mupirocin-susceptible. In contrast, there was no significant change in the rates of either MRSA (P = 0.71) or Gram-negative (P = 0.45) BSIs. In the comparison NICU, there was no significant change in rate of MSSA BSIs (P = 0.34).ConclusionDespite a substantial burden of MSSA-colonized neonates, the intervention was associated with elimination of MSSA BSI and an 82% reduction in rate of MSSA infections. A potential confounding factor was the occurrence of a cluster of mupirocin-resistant MRSA during the intervention period with the associated intensified infection prevention measures.Disclosures All authors: No reported disclosures.