Spreading the Benefits of Infection Prevention in the Neonatal Intensive Care Unit
Authors: Joseph B. Cantey, Andrea Ronchi, Pablo J. Sánchez
Journal: JAMA Pediatrics (2015)

Although infections due to Staphylococcus aureus are infrequent in the neonatal intensive care unit (NICU), they are associated with substantial morbidity and mortality. In this issue of JAMA Pediatrics, Ericson et al1 describe a 15-year (1997-2012) retrospective study with invasive S aureus infections, defined as a positive culture of blood, cerebrospinal fluid, normally sterile body fluid, or abscess for S aureus, in 348 NICUs managed by the Pediatrix Medical Group. Among 887 910 infants admitted to these NICUs, 3888 (0.4%) had at least 1 invasive S aureus infection, which occurred in 2.2% of very low-birth-weight (VLBW) infants (birth weight <1500 g) and in 0.1% of those with a birth weight of 1500 g or higher, for an estimated annual burden of more than 5000 invasive S aureus infections in NICUs in the United States alone. Most important, invasive staphylococcal infections due to methicillin-susceptible S aureus (MSSA) (occurring in 72.7% of infants [2825 of 3888]) were more frequent than those due to methicillin-resistant S aureus (MRSA) (occurring in 27.3% of infants [1063 of 3888]). Only a limited number of risk factors for infection (eg, low birth weight, gestational age, and ventilator or inotropic support) were evaluated, which were similar between the 2 groups, as was mortality overall (9.6% [237 of 2474] for MSSA vs 11.9% [110 of 926] for MRSA, P = .049) and by birth weight categories. However, a significant omission is the lack of information on the presence and duration of intravascular catheters given their known association with bloodstream infections.2 These findings are similar to those reportedpreviously by the Eunice Kennedy ShriverNational Institute of Child Health andHumanDevelopmentNeonatalResearchNetwork,3where among 8444VLBW infants born from2006 to 2008who survivedmore than 72 hours, 316 (3.7%) had bacteremia ormeningitis due toSaureus. Of these 316 infected infants, 88 (27.8% [1.0% of all infants]) had MRSA infections while 228 (72.2% [2.7%of all infants]) hadMSSA infections.Necrotizing enterocolitis, need for mechanical ventilation, and other morbidities did not differ in infants infectedwithMRSAvsMSSA, and mortality was high for both (26.1% for MRSA and 24.1% for MSSA). It is possible that virulence factors on mobile genetic elements that are shared between MRSA and MSSA have led to similar adverse outcomes. These and other reports suggest that measures to prevent MRSA infections should be broadened to include MSSA4,5 and that hospital infection control policies and practices that traditionally have focused only on MRSA should include MSSA as well.6 Prevention of all staphylococcal infections is an important goal. However, any bloodstream infection with any pathogen in preterm infants is associated with higher mortality and worse neurodevelopmental outcomes.7 Moreover, all health care–associated infections in infants of any birth weight or gestational age should be considered a preventable harm. Therefore, in the absence of an organism-specific outbreak, the paradigm for prevention of health care–associated infections has shifted from a pathogen-specific or vertical approach to a broader horizontal approach that will mitigate transmission and infection with many pathogens.8 Traditional vertical approaches reduce risk of colonization, infection, and transmission of specific pathogens, such as MRSA, by focusing on active surveillance testing to identify carriers, followed by implementation of measures aimed at preventing transmisRelated article page 1105 Editorial Opinion