Secular trends in pediatric bloodstream infections over a 20-year period at a tertiary care hospital in Germany

Objective Over the last 20 years, a number of medical innovations with impact on the incidence of bacterial and fungal bloodstream infections (BSIs) in children have been developed and implemented. Although appropriate empirical antimicrobial therapy is a prerequisite to the successful treatment of BSIs, to date, epidemiological data on long-term microbiological trends in BSIs of hospitalized children have not been available. Methods Two cohorts of pediatric patients who were hospitalized in a single-center tertiary care hospital in Germany over a 20-year time span (period A from 1985 to 1995 vs. period B from 1997 to 2006) were retrospectively analyzed and compared with respect to the epidemiology and microbiology of BSIs. Results A total of 1,646 cases of monomicrobial BSIs were detected. The rate of positive blood culture results dropped from 4.5% in period A to 2.0% in period B. The proportion of gram-positive vs. gram-negative pathogens recovered from blood cultures remained stable. Among gram-positive pathogens, an increase in enterococci (3.3% vs. 8.2%) and in coagulase-negative staphylococci (CoNS) (22.9 vs. 28.2%) was observed. In contrast, BSIs caused by Staphylococcus aureus (16.4% vs. 11.7%), Streptococcus agalactiae (4.9% vs. 2.1%), Haemophilus influenzae (7.3% vs. 0.7%), and Neisseria meningitidis (1.9% vs. 0.5%) diminished. In analyzing subgroups, an increase of enterococcal and CoNS infections was noted among patients with immunosuppression and neonatal early-onset sepsis (EOS), while a decrease was found among late-onset sepsis (LOS) cases with S. viridans. Notably, aminopenicillin-resistant enterococci and aminopenicillin- and fluoroquinolone-resistant Enterobacteriaceae all increased over time, while the overall resistance pattern was still favorable. The overall mortality rate of BSIs decreased (5.2% vs. 2.6%). Conclusions Over the 20-year study period, the spectrum of specific microorganisms among BSIs shifted, with opportunistic pathogens becoming predominant. Despite an increase in the proportion of antibiotic-resistant organisms, however, the mortality rate decreased.