Comparison of contamination rates of catheter-drawn and peripheral blood cultures

J Hosp Infect. 2005 Jun;60(2):118-21. doi: 10.1016/j.jhin.2004.10.020.


The aim of this study was to assess the sensitivity and specificity of catheter-drawn and peripheral blood cultures. Paired blood culture samples collected over a 44-month period from a 280 bed Brisbane metropolitan hospital were analysed, using standard clinical and microbiological criteria, to determine whether blood culture isolates represented true bacteraemias or contamination. Catheter-collected cultures had a specificity of 85% compared with 97% for peripheral cultures. In only two instances (0.2%) was the diagnosis of clinically significant bacteraemia made on the basis of catheter culture alone. This study concluded that catheter-collected samples are not a good test for true bacteraemia, and that peripheral cultures are more reliable when the results of the paired cultures are discordant.

Publication types

  • Comparative Study
  • Validation Study

MeSH terms

  • Bacteremia / blood
  • Bacteremia / diagnosis*
  • Bacteremia / epidemiology
  • Bacteremia / microbiology
  • Bacteriological Techniques / instrumentation
  • Bacteriological Techniques / methods
  • Blood Specimen Collection / instrumentation
  • Blood Specimen Collection / methods*
  • Blood Specimen Collection / standards
  • Catheterization, Peripheral*
  • Catheters, Indwelling*
  • Disinfection / methods
  • Equipment Contamination
  • False Negative Reactions
  • False Positive Reactions
  • Hospitals, Urban
  • Humans
  • Likelihood Functions
  • Phlebotomy / instrumentation
  • Phlebotomy / methods*
  • Phlebotomy / standards
  • Queensland / epidemiology
  • Retrospective Studies
  • Sensitivity and Specificity