Mrsa in the Nicu: An Up-and-Coming Pathogen

Abstract

Background: Hospitalized neonates are at risk of the adverse consequences of MRSA colonization and infection. Risk factors for MRSA infection in the NICU include extreme prematurity, LBW, surgery and procedures such as central lines, ventilation and drains. The incidence of MRSA colonization and infection, and characteristics of MRSA infected neonates, has not yet been published to our knowledge with respect to a Canadian NICU. Objective: To determine the incidence of MRSA colonization and invasive infection in neonates admitted to the NICU at BC Children's Hospital from 1999 through 2008. Design/Methods: The NICU database was searched for infants with at least 1 positive MRSA screening swab and/or other clinically obtained cultures positive for MRSA (including wound, eye/ear fluid, blood, urine, CSF, tracheal aspirates) from 1999-2008. A retrospective chart review of colonized and/or infected babies was performed, and cases of invasive infection were described. Results: MRSA colonization was highest in 1999 and lowest in 2001 [table 1] but has been increasing since 2005. The incidence of invasive infection varied yearly (0-50%), but remained between 31-42% over the past 3 years. Invasive infections varied from MRSA pustules/abscesses, infected surgical wounds, pneumonia, osteomyelitis, bacteremia to overwhelming sepsis. Infants with invasive infection were 28+5 wks GA, BW was 1222g, and LOS was 102 days (means). Nine of 35 babies with MRSA infection underwent a recent surgical procedure prior to onset of infection. MRSA was implicated in the cause of death in 5 babies; 4 were born at <26 wks GA, and one was born at 33wks with a congenital neurologic disorder. (table presented) Conclusions: MRSA infections appear to have caused a great degree of morbidity for neonates in the NICU, and were directly linked to mortality for 5 babies in this study. MRSA colonization has been rising, and infection will likely become an increasingly important cause of morbidity in Canadian NICUs.