Pediatric blood culture contamination rates
Abstract:
Introduction: Contaminated blood cultures result in unnecessary use and antibiotic exposure. US studies have found contamination rates of 0.6 to 6; however, the rates and risk factors of blood culture contamination (BCC) across age groups in children are not well understood.
Objective: The objective of this study was to calculate rates of BCC by pediatric age groups and identify risk factors for BCC.
Methods: This was a retrospective cohort study of 89 948 blood cultures obtained from 2014 to 2022 in outpatient and hospital settings within a multicenter health care system. Cultures with commensal organisms were considered contaminated after excluding patients with immunodeficiencies, history of malignancy, and indwelling catheters. Multivariable logistic regression models estimated odds ratios (OR) and 95% CIs for the association of risk factors and odds of BCC.
Results: Among 89 948 total blood cultures, 1594 (1.8%) were identified as likely contaminants. The BCC rate was greatest in infants: 2.0% in the 0- to 28-day-old age group, 5.4% in 29- to 90-day-old age group, and 2.7% in the 90-day- to 1-year age group. Emergency department (ED) nurses had the highest odds of contamination compared with phlebotomists (OR = 2.79, 95% CI: 2.47-3.15). Inpatient nurses had lower odds of contamination compared with phlebotomists for newborns aged 0 to 28 days (OR = 0.36, 95% CI: 0.28-0.46) but had higher odds for patients aged older than 1 year. Inpatient nurses had the highest odds compared with phlebotomists for patients aged 5 to 12 years (OR = 6.90, 95% CI: 4.08-11.75).
Conclusions: Younger patient age and ED nurse blood cultures had greater odds of contamination. Results can inform focused training on quality collection and testing techniques, as well as the creation of enhanced staffing models to increase phlebotomist collections.
Reference:
Childress K, Hartmann M, Fernandes G, Fong N, Cooch P, Kwan ML. Pediatric Blood Culture Contamination Rates and Risk Factors in a Large Integrated Health System. Hosp Pediatr. 2025 Jun 13:e2024008184. doi: 10.1542/hpeds.2024-008184. Epub ahead of print. PMID: 40506055.