Long-term trends in the epidemiology of neonatal sepsis and antibiotic susceptibility of causative agents

Neonatology. 2010;97(1):22-8. doi: 10.1159/000226604. Epub 2009 Jul 2.


Background: In an era with increased maternal antibiotic use, patterns in early- and late-onset sepsis and antibiotic susceptibility may have changed.

Objectives: To identify longitudinal trends in causative microorganisms for neonatal sepsis and analyze antibiotic susceptibility of all blood isolates of infants with sepsis.

Methods: Early- and late-onset sepsis cases from 29 years (1978-2006) were studied retrospectively, in five clusters of 5 years (period I-V) and one cluster of 4 years (period VI), including antibiotic susceptibility profiles of blood isolates during the years 1999-2006.

Results: The incidence of early-onset sepsis decreased (p < 0.01) from 4% during period I (1978-1982) to 1.2% during period VI (2003-2006). 78% of the infants with group B streptococcal (GBS) sepsis were premature during period I, compared to 47% during period VI (p < 0.05). The incidence of early-onset Gram-negative infections remained low during all periods. The incidence of late-onset sepsis, predominantly caused by coagulase-negative staphylococci (CONS) and Staphylococcus aureus, increased since period III from 7.1 to 13.9% in period VI (p < 0.01). Infections due to fungi or yeasts were rare (incidence <0.3%). The majority of CONS blood isolates were oxacillin-resistant, but vancomycin-susceptible. 95% of CONS blood isolates were susceptible for first-generation cephalosporins. Amoxicillin/clavulanic acid-resistant Escherichia coli were infrequent causes of infection.

Conclusions: The incidence of early-onset sepsis mainly caused by GBS decreased. In contrast, the incidence of late-onset sepsis, predominantly caused by CONS, increased significantly. The incidence of fungal and yeast infections remained low. The majority of CONS blood isolates were susceptible for first-generation cephalosporins.

MeSH terms

  • Anti-Bacterial Agents / therapeutic use
  • Bacteremia / drug therapy
  • Bacteremia / epidemiology
  • Bacteremia / microbiology
  • Drug Resistance, Microbial / drug effects
  • Drug Resistance, Multiple, Bacterial / drug effects
  • Gram-Negative Bacterial Infections / drug therapy
  • Gram-Negative Bacterial Infections / epidemiology*
  • Gram-Negative Bacterial Infections / microbiology*
  • Gram-Positive Bacterial Infections / drug therapy
  • Gram-Positive Bacterial Infections / epidemiology*
  • Gram-Positive Bacterial Infections / microbiology*
  • Humans
  • Infant, Newborn
  • Infectious Disease Transmission, Vertical
  • Microbial Sensitivity Tests
  • Netherlands / epidemiology
  • Retrospective Studies
  • Risk Factors
  • Systemic Inflammatory Response Syndrome / drug therapy
  • Systemic Inflammatory Response Syndrome / epidemiology*
  • Systemic Inflammatory Response Syndrome / microbiology*


  • Anti-Bacterial Agents