40 17-year retrospective population-based study of neonatal sepsis in British Columbia

Abstract Background Sepsis is responsible for about one third of neonatal deaths worldwide. Preterm infants are at higher risk of sepsis than term infants. However, contemporary population-based data are scarce and the risks of neonatal sepsis associated with gestational age at delivery are understudied. Objectives To determine the population-based incidence of neonatal sepsis in British Columbia (BC), Canada and to examine changes in the risk of sepsis by gestational age at delivery. Design/Methods A population-based retrospective cohort study including all children born in BC from 2004 to 2020, capturing hospital admissions up to the first 28 days of life. Data were obtained from the BC Perinatal Data Registry. The primary outcome was sepsis, identified by ICD-10 diagnostic codes or a confirmed positive blood culture abstracted from medical charts. Secondary outcomes included explicit sepsis (ICD-10 codes explicitly mentioning sepsis), implicit sepsis (cases of severe infection associated with an organ dysfunction ICD-10 code), culture-positive sepsis (bacterial or fungal blood culture), and septic shock. Incidence proportions were calculated as the number of sepsis cases per 1,000 live births, stratified by gestational age (in weeks) and birth year. Results Of the 722,264 live-born infants in the cohort, 3,537 had sepsis (4.86 per 1,000 live births). In preterm infants (<37 weeks), the incidence was 23.9 per 1,000 live births versus 2.8 per 1,000 in term infants. This difference highlights the increased vulnerability of preterm infants to sepsis, which may be due to their underdeveloped immune systems, organs, or other physiological factors. For secondary outcomes, there were 793 cases of culture-positive sepsis, 2,635 cases of explicit sepsis, 280 cases of implicit sepsis and 244 cases of septic shock. The incidence of all types of sepsis decreased with increasing gestational age (Figure 1). Bacterial sepsis was more common than viral or fungal sepsis (overall incidence of 3.5 cases per 1,000 live births). Fungal sepsis had higher incidence at <31 weeks (6.12 cases per 1,000 live births at 25 weeks). Since 2004, the incidence of sepsis has been decreasing in BC. Conclusion This study found that the incidence of sepsis in preterm infants was lower than that reported in the literature, which tends to focus on NICU populations. The population-level incidence of sepsis was much higher in preterm compared with term infants. Therefore, targeted prevention strategies and early interventions for preterm infants are essential to reduce the burden of sepsis and improve neonatal outcomes at a population level.