title: Comparison of contamination rates of catheter-drawn and peripheral blood cultures.
abstract: 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.
authors.affiliation: Queensland University of Technology, Brisbane, Queensland, Australia. e.mcbryde@qut.edu.au
authors.forename: E S
authors.initials: ES
authors.lastname: McBryde
authors.forename: M
authors.initials: M
authors.lastname: Tilse
authors.forename: J
authors.initials: J
authors.lastname: McCormack
mesh_terms: D016470:Bacteremia / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D001431:Bacteriological Techniques / Q000295:instrumentation / Q000379:methods; D001800:Blood Specimen Collection / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D002406:Catheterization, Peripheral; D002408:Catheters, Indwelling; D004203:Disinfection / Q000379:methods; D004866:Equipment Contamination; D005188:False Negative Reactions; D005189:False Positive Reactions; D006786:Hospitals, Urban; D006801:Humans; D016013:Likelihood Functions; D018962:Phlebotomy / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D011793:Queensland / Q000453:epidemiology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity