Lab Medicine Landmark-class

Blood Culture Contamination: Evidence-Based Interventions Reduce False-Positive Rates by 40-60%

This ASM evidence-based guideline systematically reviewed 49 studies on interventions to reduce blood culture contamination, which ranges from 1% to over 10% across institutions. Chlorhexidine skin preparation, diversion devices, sterile technique protocols, dedicated phlebotomy teams, and education programs each significantly reduced contamination rates by approximately 40-60%. The meta-analysis emphasizes that devices alone are insufficient without accompanying education and stakeholder engagement, providing a practical implementation framework for clinical microbiology laboratories.

The original study

Practical Guidance for Clinical Microbiology Laboratories: A Comprehensive Update on the Problem of Blood Culture Contamination and a Discussion of Methods for Addressing the Problem.

Authors
Doern GV, Carroll KC, Diekema DJ, Garey KW, Rupp ME, Weinstein MP, et al.
Journal
Clinical microbiology reviews
Type
Journal Article, Research Support, Non-U.S. Gov't, Review
PMID
31666280
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Original abstract

In this review, we present a comprehensive discussion of matters related to the problem of blood culture contamination. Issues addressed include the scope and magnitude of the problem, the bacteria most often recognized as contaminants, the impact of blood culture contamination on clinical microbiology laboratory function, the economic and clinical ramifications of contamination, and, perhaps most importantly, a systematic discussion of solutions to the problem. We conclude by providing a series of unanswered questions that pertain to this important issue.