Early-onset sepsis in very preterm neonates in Australia and New Zealand, 2007–2018

Abstract

ObjectiveTo evaluate the epidemiology and population trends of early-onset sepsis in very preterm neonates admitted to neonatal intensive care units (NICU) in Australia and New Zealand.DesignRetrospective observational cohort study using a dual-nation registry database.Setting29 NICUs that have contributed to the Australian and New Zealand Neonatal Network.ParticipantsNeonates born at <32 weeks’ gestation born between 2007 and 2018 and then admitted to a NICU.Main outcome measuresMicroorganism profiles, incidence, mortality and morbidity.ResultsOver the 12-year period, 614 early-onset sepsis cases from 43 178 very preterm admissions (14.2/1000 admissions) were identified. The trends of early-onset sepsis incidence remained stable, varying between 9.8 and 19.4/1000 admissions (linear trend, p=0.56). The leading causative organisms wereEscherichia coli(E. coli) (33.7%) followed by group BStreptococcus(GBS) (16.1%). The incidence ofE. coliincreased between 2007 (3.2/1000 admissions) and 2018 (8.3/1000 admissions; p=0.02). Neonates withE. colihad higher odds of mortality compared with those withGBS(OR=2.8, 95% CI 1.2 to 6.1). Mortality due toGBSdecreased over the same period (2007: 0.6/1000 admissions, 2018: 0.0/1000 admissions; p=0.01). Early-onset sepsis tripled the odds of mortality (OR=3.0, 95% CI 2.4 to 3.7) and halved the odds of survival without morbidity (OR=0.5, 95% CI 0.4 to 0.6).ConclusionEarly-onset sepsis remains an important condition among very preterm populations. Furthermore,E. coliis a dominant microorganism of very preterm early-onset sepsis in Australia and New Zealand. Rates ofE. colihave been increasing in recent years, whileGBS-associated mortality has decreased.