Early Onset Neonatal Sepsis in Canada: 2011-2012

Abstract

BACKGROUND: Canadian and US studies suggest that the organisms responsible for early-onset neonatal sepsis (EONS) are changing, with an increase in Escherichia coli (EC) as well as antibiotic-resistant organisms. Current Canadian guidelines for prevention and treatment of EONS are based on Group B streptococcus (GBS) as the likely organism. Population-level data may inform updates to these national strategies. OBJECTIVES: To determine the incidence, types of organisms and corresponding resistance patterns involved in EONS in Canada. To identify how the organisms are affected by maternal antibiotic prophylaxis and other factors. DESIGN/METHODS: Cases of EONS (defined as positive blood and/or cerebrospinal fluid (CSF) culture at <7 days of age) between January 2011 and December 2012 were identified through the Canadian Paediatric Surveillance Program (CPSP). Neonates were excluded if they were asymptomatic with a positive culture likely to be a contaminant, or if the CSF culture was positive as a result of an intracranial procedure. RESULTS: Over the 2-year period, 127 cases meeting our criteria were identified, and there were 754,849 total Canadian live births. The incidence for EONS was 0.17/1000 live births. 79.5% of cases presented within the first 24 hours of life, while 15% presented between 72 h-7 days. GBS accounted for 41.7% of cases, while EC accounted for 35.4%. Resistance was noted in 33.9% of cases overall. 55.6% of EC were resistant, with ampicillin resistance being the most common. The species of infecting organism was significantly associated with gestational age, very low birth weight, age at presentation, the mother having received GBS prophylaxis, and rupture of membranes lasting more than 18 h. GBS was most common in term and EC in preterm neonates. The overall EONS case fatality rate was 11%, with most of these being deaths from EC. CONCLUSION: Our study suggests a lower rate of EONS than historically suggested, with differing dominant organisms based on gestational ages of the neonates. Later ages at presentation and high rates of resistance especially among EC cases further complicate the picture. We recommend a review of the Canadian prevention and treatment guidelines based on our findings.