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