Clinical outcomes of Staphylococcus capitis isolation from neonates, England, 2015–2021: A retrospective case–control study

Objective: Staphylococcus capitis, a coagulase-negative staphylococci (CoNS) species, has been increasingly detected from UK sterile site samples and has caused neonatal unit outbreaks worldwide. We compared survival to discharge and 30-day mortality for the detection of S. capitis versus other CoNS species. 

Methods: In this retrospective case–control study, we included hospitalised infants with any CoNS species detected from a normally sterile body site up to 90 days of age. We linked English laboratory reports from the Second Generation Surveillance System database, mortality data from the Personal Demographics Service, and neonatal unit admissions from the National Neonatal Research Database. In primary analysis, multivariable logistic regression was used, with two co-primary outcomes: survival to discharge and death within 30 days of positive specimen date. Sensitivity analyses using multiply imputed datasets followed. 

Results: We identified 16636 CoNS episodes relating to 13745 infants. CoNS episodes were highest among infants born extremely preterm (22–27 weeks) and with extremely low birth weight (400–999g). In primary analysis, there were no differences in survival to discharge (p=0.71) or 30-day mortality (p=0.77) between CoNS species. In sensitivity analyses, there were no differences in outcomes between infection with four of the most common CoNS species (Staphylococcus epidermidis, S. capitis, Staphylococcus haemolyticus and Staphylococcus warneri) but the remaining CoNS species were at higher risk of adverse outcomes when treated in aggregate. 

Conclusion: Infants with S. capitis detected from sterile site samples did not experience significant differences in either survival to discharge or 30-day mortality compared with infants with detection of other common CoNS species.