Clinical Outcomes in Methicillin-Resistant Staphylococcus aureus-Colonized Neonates in the Neonatal Intensive Care Unit

Abstract

Background: Methicillin-resistent Staphylococcus aureus (MRSA) colonization can persist for prolonged periods, and patient-related factors are associated with persistent carriage in adults. However, such knowledge is lacking among neonates. Objectives: To better understand the outcome of MRSA-colonized neonates in the neonatal intensive care unit (NICU), we prospectively followed all colonized neonates until decolonization over 39 months and determined the incidence, duration of colonization, clinical outcomes and risk factors associated with prolonged carriage of MRSA. Methods: Nasal and inguinal cultures were obtained from all newly admitted neonates following an outbreak of MRSA. Weekly and 1–2 monthly cultures were obtained from all hospitalized and discharged neonates colonized with MRSA, respectively, until 2 consecutive cultures were negative. Results: 152 of 1,456 (10.4%) neonates became colonized. The mean time to acquire MRSA colonization was 17.1 ± 40.7 (range 1–471) days. The median time to decolonization was 36 days. About 20% of decolonized patients had been colonized for a prolonged period of ≧160 days. 47.5% of colonized patients were sent home colonized, and none with prolonged carriage developed MRSA-related infections in the following 6 months in contrast to 6 infants (3.9%) who developed MRSA sepsis during hospitalization. The only risk factor associated with prolonged carriage was the concurrent colonization of both the inguinal and nasal areas on admission. Conclusion:Nearly all neonates with acquired colonization became decolonized either prior to or after discharge from NICU. A significant percentage failed to decolonize prior to hospital discharge, but almost all decolonized by 30 months in the community without evidence of systemic or local infections.