Objective To 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.
Design Retrospective observational cohort study using a dual-nation registry database.
Setting 29 NICUs that have contributed to the Australian and New Zealand Neonatal Network.
Participants Neonates born at <32 weeks’ gestation born between 2007 and 2018 and then admitted to a NICU.
Main outcome measures Microorganism profiles, incidence, mortality and morbidity.
Results Over 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 were Escherichia coli (E. coli) (33.7%) followed by group B Streptococcus (GBS) (16.1%). The incidence of E. coli increased between 2007 (3.2/1000 admissions) and 2018 (8.3/1000 admissions; p=0.02). Neonates with E. coli had higher odds of mortality compared with those with GBS (OR=2.8, 95% CI 1.2 to 6.1). Mortality due to GBS decreased 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).
Conclusion Early-onset sepsis remains an important condition among very preterm populations. Furthermore, E. coli is a dominant microorganism of very preterm early-onset sepsis in Australia and New Zealand. Rates of E. coli have been increasing in recent years, while GBS-associated mortality has decreased.
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information.
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Collaborators The authors are grateful to the ANZNN for providing access to their registry database. Special thanks to all Advisory Council Members of the ANZNN: Advisory Council Members of ANZNN (*denotes ANZNN Executive). Australia: Scott Morris (Flinders Medical Centre, SA), Peter Schmidt (Gold Coast University Hospital, QLD), Larissa Korostenski (John Hunter Children’s Hospital, NSW), Mary Sharp, Andy Gill*, Jane Pillow* (King Edward Memorial and Perth Children’s Hospitals, WA), Jacqueline Stack (Liverpool Hospital, NSW), Pita Birch, Karen Nothdurft* (Mater Mother’s Hospital, QLD), Dan Casalaz, Jim Holberton* (Mercy Hospital for Women, VIC), Alice Stewart, Rod Hunt* (Monash Medical Centre, VIC), Lucy Cooke* (Neonatal Retrieval Emergency Service Southern Queensland, QLD), Lyn Downe (Nepean Hospital, NSW), Michael Stewart (Paediatric Infant Perinatal Emergency Retrieval, VIC), Andrew Berry (NSW Newborn & Paediatric Emergency Transport Service), Leah Hickey (Royal Children’s Hospital, VIC), Peter Morris (Royal Darwin Hospital, NT), Tony De Paoli, Naomi Spotswood* (Royal Hobart Hospital, TAS), Srinivas Bolisetty, Kei Lui* (Royal Hospital for Women, NSW), Mary Paradisis (Royal North Shore Hospital, NSW), Mark Greenhalgh, (Royal Prince Alfred Hospital, NSW), Pieter Koorts (Royal Brisbane and Women’s Hospital, QLD), Carl Kuschel, Lex Doyle, (Royal Women’s Hospital, VIC), John Craven (SAAS MedSTAR Kids, SA), Clare Collins (Sunshine Hospital, VIC), Andrew Numa (Sydney Children’s Hospital, NSW), Hazel Carlisle (The Canberra Hospital, ACT), Nadia Badawi, Himanshu Popat (The Children’s Hospital at Westmead, NSW), Guan Koh (The Townsville Hospital, QLD), Jonathan Davis (Western Australia Neonatal Transport Service), Melissa Luig* (Westmead Hospital, NSW), Bevan Headley, Chad Andersen* (Women’s & Children’s Hospital, SA). New Zealand: Nicola Austin (Christchurch Women’s Hospital), Brian Darlow (Christchurch School of Medicine), Liza Edmonds (Dunedin Hospital), Lindsay Mildenhall (Middlemore Hospital), Mariam Buksh, Malcolm Battin* (Auckland City Hospital), Jutta van den Boom (Waikato Hospital), Vaughan Richardson, * (Wellington Women’s Hospital). We also wish to acknowledge ANZNN Executive that are not members of hospitals contributing data: Georgina Chambers* (National Perinatal Epidemiology and Statistics Unit, University of New South Wales); Victor Samuel Rajadurai* (KK Women’s and Children’s Hospital, Singapore); David Barker* (Whangarei Hospital, NZ), Anjali Dhawan* (Blacktown Hospital, NSW), Barbara Hammond* (Whanganui Hospital, NZ), Natalie Merida* (consumer), Linda Ng* (ACNN).
Contributors HLD conceptualised and designed the study, carried out the data analysis, drafted the initial manuscript and reviewed and revised the protocol and manuscript. KT and KL conceptualised and designed the study, supervised the data analysis and reviewed and revised the protocol and manuscript. PSS conceptualised and designed the study and reviewed and revised the protocol and manuscript. NCA assisted the acquisition of data and reviewed and revised the protocol and manuscript. SSWC assisted the acquisition of data, improved the accuracy and validity of the data analysis, and reviewed and revised the protocol and manuscript. KT is the author acting as guarantor.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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