Changes in incidence and etiology of early-onset neonatal infections 1997–2017 – a retrospective cohort study in western Sweden

Abstract

BackgroundThe objective of the study was to evaluate data on early-onset neonatal invasive infections in western Sweden for the period 1997–2017. To identify changes in incidence, etiology and mortality and compare to previous studies from the same area starting from 1975.MethodsObservational epidemiological, retrospective study on infants 0–6 days of age with a positive culture in blood and/or cerebrospinal fluid between 1997 and 2017. A comparison was made of the incidence between 2008 and 2017 compared to 1997–2007. Changes in the incidence of infections due to Group B streptococci, Staphylococcus aureus and aerobic Gram-negative rods were assessed from 1975.ResultsThe total incidence, including both recognized pathogens and commensals as causative agents, was 1.1/1000 live births. The incidence declined from 1.4/1000 LB in 1997–2007 to 0.9/1000 LB in 2008–2017 but the case-fatality rate remained unchanged, (8/119 vs 7/90), at 7%. Among the 209 patients identified during 1997–2017 with sepsis or meningitis the most common organisms were Group B streptococci (40%, 84/209), S. aureus (16%, 33/209) and E. coli (9%, 18/209). The incidence of Group B streptococci infections went from 0.9/1000 live births 1987–1996 to 0.45/1000 live births 1997–2017 and all cases were within 72 h. The proportion of extremely preterm infants (< 28 weeks gestation) rose steadily during the study period but there was no rise in infections due to Gram-negative organisms. The spectrum of cultured organisms changed after 72 h as commensal organisms started to emerge.ConclusionThere has been a decrease in the incidence of neonatal early-onset infections compared to previous studies in western Sweden. The incidence of GBS infections was not as low as in other reports. Further studies are needed to assess if screening-based intra partum antimicrobial prophylaxis instead of a risk factor-based approach for identifying candidates for intrapartum antimicrobial prophylaxis would be a better option for this study area.Key notes This study is one of the longest running follow-ups in the world, a follow-up of 43 years of early-onset neonatal infections.The incidence of early-onset GBS infections is higher in Western Sweden compared to other local reports.No difference in the incidence of early-onset GBS depending on the definition of early-onset being within 72 h or 7 days of life.

Early-Onset Sepsis in Neonates - A Population-Based Study in South-West Norway From 1996 to 2018

“…The overall incidence of EOS was 0.97/1000 LB, comparable to reports from other epidemiological studies from Sweden (0.9) ( 3 ), United Kingdom (0.7) ( 16 ) and the United States (0.77–1.08) ( 1 , 5 , 17 ). We found a 24-fold higher incidence of EOS in extremely preterm infants compared to term infants, a slightly lower ratio than the 30-fold higher EOS rate reported by Stoll et al ( 5 ).…”

“…Although most EOS cases occur in term infants, incidence and infection-attributable mortality is higher in preterm infants, inversely related to gestational age (GA) (2). In many countries and regions the incidence of EOS has decreased in the past decades, in particular after implementing effective intrapartum antibiotic prophylaxis (1,(3)(4)(5)(6). Among term (GA ≥ 37 weeks) and moderately preterm infants (GA 28-36 weeks) with EOS, group B streptococci (GBS) are the dominant pathogens identified in blood cultures (5)(6)(7).…”

A decade of neonatal sepsis caused by gram-negative bacilli—a retrospective matched cohort study

“…The incidence of neonatal GNB-sepsis in the region was 0.35/1000 live born neonates and remained unchanged during the study period. The incidence of GNB-EOS was 0.11/1000 live births which is about half of what recently has been reported from the western part of Sweden, where the incidence of GNB-EOS was 0.25/1000 live births [9]. The difference is substantial but might be influenced by methodological differences.…”

“…Infants with gram-negative bacilli (GNB)-LOS are associated with a higher mortality compared to grampositive bacteria (GPB)-LOS [7,8]. Studies from Sweden in the last decade report an incidence of early-onset sepsis (EOS) of 0.9/1000 live births with a case fatality rate (CFR) of 7% and the GNB-EOS incidence of 0.25/1000 live born with a CFR of 13% [9]. There are no previous studies on the incidence or the CFR of neonatal GNB-LOS in Sweden.…”

Modern approaches to diagnosis and treatment of early-onset neonatal sepsis

“…EOS develops in the first 72 hours of life and is usually the result of intrauterine infection by transplacental or ascending [14]. The global microbial landscape of sepsis in EOS is represented by Streptococcus agalactiae, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae pathogens [15,16].…”