Trends of Pediatric Bloodstream Infections in Stockholm, Sweden: A 20-year Retrospective Study.

Background: The etiology of bloodstream infections (BSIs) changes over time due to updated immunization programs, new antibiotic-use strategies, changes in patient mix and travel. Continuous surveillance can guide empiric therapy and identify targets for prevention.

Method: We conducted a descriptive retrospective analysis among children <18 years of age who were detected with BSI between July 1998 and June 2018 for changes in the incidence, risk factors, and etiology of BSI in a Swedish tertiary hospital (Karolinska University Hospital).

Results: We evaluated 2079 episodes of BSI. During the study period, the incidence of BSI in children 0-17 years of age decreased (τ = -0.45, P = 0.016), which was most evident among children 3 months to 2 years of age (τ = -0.59, P = 0.0006) and in early neonatal period (0-7 days; τ = -0.44, P = 0.0069). These were explained by the reduced occurrence of Streptococcus pneumoniae in children 3 months to 2 years of age and Streptococcus agalactiae and Candida spp. in neonates. Staphylococcus aureus was the commonest pathogen, accounting for 31.6% of episodes. The proportion of hospital-acquired infection was higher in patients with underlying risk factors (47.6% vs. 2.6%). The etiology of hospital-acquired infection BSI was more diverse than that of community-acquired infections and was related to underlying risk factors. The crude mortality rate was 5.7%. For children admitted to the neonatal ward, the mortality was 17.6%, but declined (τ = -0.469, P = 0.004) over the study period.

Conclusions: There was a decreasing trend of pediatric BSI and mortality over last 20 years, which was associated with pneumococcal immunization and antimicrobial prophylaxis for high-risk patients.