Background: Contamination of blood culture (BC) bottles impedes medical practice, often leading to additional unnecessary diagnostic procedures or treatments. We examined the effect of various methods of staff interventions on rates of BC contamination.
Methods: Instructions for BC collection were compiled by a structured protocol. Personal and general staff guidance was performed. A poster with detailed instructions was placed in every phlebotomy room. A detailed review including a personal interview with the phlebotomist was performed for every case of contamination. This intervention was performed for 6 months (July/2016-jan/2017) in a single tertiary pediatric center.
Results: Of 12,407 BC bottles obtained 261 (2.1%) were contaminated, comprising 32.1% (261/816) of all positive BC. Contamination rate was reduced from 2.2% during the year preceding the study period, to 1.9% (p>0.05). BC obtained from patients aged 0-4 days had the lowest contamination rate (0.35%). Contamination rates per department: emergency department (ED) (1.6%), Pediatric Intensive Care Unit (PICU) (2.2%), Oncology (3.1%), General Pediatrics (2.4%). 78% of positive BC obtained from patients discharged from ED following evaluation were contaminated rather than true infections. Contamination rates per draw method: peripheral venipuncture (1.8%), arterial line (PICU only) (2.1%), central venous catheters (CVC) (3.6% mainly Oncology).
Conclusions: Reducing contamination of BC is challenging. Contamination rates were reduced by implementing a pre-set protocol (non-significant trend). Contamination rate were lowest in the early neonatal period and highest in cultures obtained from CVC. Long-term educational efforts are needed to keep BC contamination rates below 2%.
