Contamination of blood cultures from arterial catheters vs peripheral venipuncture in critically ill patients: A multicenter prospective observational study - Contamination of blood cultures from arterial catheters (CONTACT study)

Of 1655 episodes of blood culture from December 2018 to July 2021, 590 paired blood cultures were enrolled, and 6.9% episodes had true bloodstream infection. In blood cultures from arterial catheters, 6.0% were positive, and 0.3% were contaminated; in venipuncture, 6.1% were positive, and 0.7% were contaminated. The estimated difference in contamination proportion (arterial catheter - venipuncture) was -0.3% (upper limit of one-sided 95% confidence interval [CI], +0.3%).