Epidemiology and Mortality of Invasive Staphylococcus aureus Infections in Hospitalized Infants

Area of Science:

• Neonatal Intensive Care Unit (NICU) research
• Infectious disease epidemiology
• Pediatric critical care medicine

Background:

• Staphylococcus aureus has historically been a major cause of infant morbidity and mortality in the NICU.
• The current incidence and mortality rates of late-onset invasive S. aureus infections in hospitalized infants are not well-established.

Purpose of the Study:

• To estimate the incidence of late-onset invasive Staphylococcus aureus infections among hospitalized infants in the US.
• To determine the mortality attributable to these infections in hospitalized infants.

Main Methods:

• Retrospective cohort study using an emulated trial design.
• Analysis of data from a national sample of 315 NICUs in the US between 2016 and 2021.
• Inclusion of infants aged at least 4 postnatal days, focusing on birth weight and postnatal age as primary exposures.

Main Results:

• An overall incidence of 37.6 invasive S. aureus infections per 10,000 infants was observed.
• Very low birth weight (VLBW) infants (<1500 g) had a >20-fold higher incidence compared to infants weighing ≥1500 g.
• Invasive infections were associated with a 5.3% absolute increase in mortality rate, with most deaths occurring in VLBW infants.

Conclusions:

• Late-onset invasive S. aureus infections disproportionately affect VLBW infants, contributing significantly to mortality.
• Targeted infection prevention and control measures are essential to reduce the burden of S. aureus infections in this high-risk neonatal population.