Coagulase-Negative Staphylococcal Infections in the Neonatal Intensive Care Unit

Abstract

Background.Coagulase-negative staphylococci (CoNS) are the most commonly isolated pathogens in the neonatal intensive care unit (NICU). CoNS infections are associated with increased morbidity, including neurodevelopmental impairment.Objective.To describe the epidemiology of CoNS infections in the NICU. To determine mortality among infants with definite, probable, or possible CoNS infections.Methods.We performed a retrospective cohort study of all blood, urine, and cerebrospinal fluid cultures from samples obtained from infants aged <121 postnatal days.Setting.A total of 248 NICUs managed by the Pediatrix Medical Group from 1997 to 2009.Results.We identified 16,629 infants with 17,624 episodes of CoNS infection: 1,734 (10%) definite, 3,093 (17%) probable, and 12,797 (73%) possible infections. Infants with a lower gestational age and birth weight had a higher incidence of CoNS infection. When controlling for gestational age, birth weight, and 5-minute Apgar score, we found that infants with definite, probable, or possible CoNS infection had lower mortality (odds ratio [OR], 0.74 [95% confidence interval {CI}: 0.61, 0.89], 0.68 [95% CI, 0.59, 0.79], and 0.69 [95% CI, 0.63, 0.76], respectively) compared with infants who had negative culture results (P<.001). No significant difference in overall mortality was found in infants who had definite CoNS infection compared with those who had probable or possible CoNS infection (OR, 0.93 [95% CI, 0.75, 1.16] and 0.85 [95% CI,0.70,1.03], respectively).Conclusions.CoNS infection was strongly related to lower gestational age and birth weight. Infants with clinical sepsis and culture-positive CoNS infection had lower mortality rates than infants with clinical sepsis and negative blood culture results. No difference in mortality between infants with a diagnosis of definite, probable, or possible CoNS infection was observed.