Rapid dissemination of Staphylococcus aureus in the neonatal intensive care unit is associated with invasive infection.

Staphylococcus aureus is a leading cause of severe infections in neonatal intensive care units (NICUs). We present results of precision surveillance of S. aureus carriage and invasive infection in a cohort study of high-risk infants in the NICU with the goal of identifying novel strategies for prevention and control. Using whole genome sequence guided epidemiology over a 3-year timeframe, we identify spatial and temporal links for transmission between babies, suggesting shared spaces, caregivers, and physical proximity as major risks for transmission in the NICU. Moreover, environmental surveillance reveals potential environmental reservoirs of S. aureus. Remarkably, specific clusters of S. aureus strains that are associated with invasive infection are also detected in more infants over time during routine surveillance, suggesting a strong link between the rate of dissemination and disease in this vulnerable population. Overall, our findings demonstrate a strong association amongst colonization, transmission, persistence, and the development of invasive infections, underscoring the importance of targeted measures to prevent S. aureus infections in the NICU setting.