To evaluate data for the period 2004-2013 to identify changes in demographics, pathogens, and outcomes in a single, level IV neonatal intensive care unit.

Sepsis episodes were identified prospectively and additional information obtained retrospectively from infants with sepsis while in the neonatal intensive care unit from 2004 to 2013. Demographics, hospital course, and outcome data were collected and analyzed. Sepsis was categorized as early (≤3 days of life) or late-onset (>3 days of life).

Four hundred fifty-two organisms were identified from 410 episodes of sepsis in 340 infants. Ninety percent of cases were late-onset. Rates of early-onset sepsis remained relatively static throughout the study period (0.9 per 1000 live births). For the first time in decades, most (60%) infants with early-onset sepsis were very low birth weight and Escherichia coli (45%) replaced group B streptococcus (36%) as the most common organism associated with early-onset sepsis. Rates of late-onset sepsis, particularly due to coagulase-negative staphylococci, decreased significantly after implementation of several infection-prevention initiatives. Coagulase-negative staphylococci were responsible for 31% of all cases from 2004 to 2009 but accounted for no cases of late-onset sepsis after 2011.

The epidemiology and microbiology of early- and late-onset sepsis continue to change, impacted by targeted infection prevention efforts. We believe the decrease in sepsis indicates that these interventions have been successful, but additional surveillance and strategies based on evolving trends are necessary.