Long-Term Trends in the Epidemiology of Neonatal Sepsis and Antibiotic Susceptibility of Causative Agents

<i>Background:</i> In an era with increased maternal antibiotic use, patterns in early- and late-onset sepsis and antibiotic susceptibility may have changed. <i>Objectives:</i> To identify longitudinal trends in causative microorganisms for neonatal sepsis and analyze antibiotic susceptibility of all blood isolates of infants with sepsis. <i>Methods:</i> 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. <i>Results:</i> 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 <i>Staphylococcus aureus</i>, 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 <i>Escherichia coli</i> were infrequent causes of infection. <i>Conclusions:</i> 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.