MICROBIOLOGY| Volume 53, ISSUE 4, P520-529, June 2021

Download started.


Blood culture quality assurance: what Australasian laboratories are measuring and opportunities for improvement

  • Juliet Elvy
    Address for correspondence: Dr Juliet Elvy, Department of Microbiology, Medlab Nelson Marlborough, Nelson, New Zealand.
    The Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP), Sydney, NSW, Australia

    Department of Microbiology, Wellington Southern Community Laboratories, Wellington Hospital, Wellington, New Zealand

    Department of Microbiology, Medlab Nelson Marlborough, Nelson, New Zealand
    Search for articles by this author
  • Debra Walker
    The Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP), Sydney, NSW, Australia
    Search for articles by this author
  • Elizabeth Haremza
    The Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP), Sydney, NSW, Australia
    Search for articles by this author
  • Katherine Ryan
    The Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP), Sydney, NSW, Australia
    Search for articles by this author
  • Arthur J. Morris
    The Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP), Sydney, NSW, Australia

    Clinical Microbiology Laboratory, LabPLUS, Auckland City Hospital, Auckland, New Zealand
    Search for articles by this author
Published:December 23, 2020DOI:


      Blood cultures are among the most important specimen types received and processed by the microbiology laboratory. Several publications list which variables should be measured to ensure quality. We undertook a qualitative structured questionnaire of Australian and New Zealand clinical microbiology laboratories to document current blood culture practices and to determine whether expected quality standards are being met. Questions included a wide range of pre-analytical, analytical, and post-analytical aspects of blood cultures from adults. The responses from 71 laboratories were analysed. Compliance was high for use of a biological safety cabinet (90%), incubating for 5 days (86%), and commenting on likely contaminants (85%). While Gram stains were reported within 2 hours during normal hours (93%), reporting was slower after hours (59%), p<0.001. The volume of blood collected for a clinical episode was poorly monitored with only 11% (n=8) of laboratories regularly auditing the number of blood culture sets and 3% (n=2) monitoring adequacy of fill. Most laboratories received blood cultures from off-site with just 34% (n=21) meeting guidance for loading bottles onto the analyser within 4 hours. More laboratories met standards for loading bottles onto the analyser during working hours than after hours: 87% vs 56%, p<0.001. Most laboratories did not monitor the contamination rate, 56% (n=40), and only 27% (n=19) knew their rate was below the guidance threshold of less than –3%. Considerable opportunities exist to improve quality assurance of blood culture practice in Australia and New Zealand, especially for the most critical aspect affecting culture sensitivity, the volume of blood collected.

      Key words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Pathology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Howell M.D.
        • Davis A.M.
        Management of sepsis and septic shock.
        JAMA. 2017; 317: 847-848
        • Rhodes A.
        • Evans L.E.
        • Alhazzani W.
        • et al.
        Surviving sepsis campaign: international guidelines for management of sepsis and septic shock: 2016.
        Crit Care Med. 2017; 45: 486-552
        • Cohen J.
        • Vincent J.-L.
        • Adhikari N.K.J.
        • et al.
        Sepsis: a roadmap for future research.
        Lancet Infect Dis. 2015; 15: 581-614
      1. Standards Unit, National Infection Service, Public Health England. UK SMI B 37: Investigation of Blood Cultures (For Organisms Other Than Mycobacterium Species). Public Health England, London2019
        • Baron E.J.
        • Weinstein M.P.
        • Dunne W.M.
        • et al.
        Blood Cultures IV. Cumitech Cumulative Techniques and Procedures in Clinical Microbiology 1C.
        ASM Press, Washington, DC2015
        • Clinical Laboratory Standards Institute (CLSI)
        Principles and Procedures for Blood Cultures. CLSI document M47-A.
        CLSI, Wayne, PA2007
        • Wilson M.L.
        • Weinstein M.P.
        • Reller L.B.
        Manual of Clinical Microbiology.
        12th ed. ASM Press, Washington, DC2019 (Chapter 4, Laboratory detection of bacteremia and fungemia)
        • McElvania E.
        • Singh K.
        Manual of Clinical Microbiology.
        12th ed. ASM Press, Washington, DC2019 (Chapter 19, Specimen collection, transport, and processing: bacteriology)
        • Cockerill F.R.
        • Wilson J.W.
        • Vetter E.A.
        • et al.
        Optimal testing parameters for blood cultures.
        Clin Infect Dis. 2004; 38: 1724-1730
        • Lee Andrew
        • Stanley Mirrett
        • Barth Reller L.
        • et al.
        Detection of bloodstream infections in adults: how many blood cultures are needed?.
        J Clin Microbiol. 2007; 45: 3546-3548
        • Bouza E.
        • Sousa D.
        • Rodrıguez-Creixems M.
        • et al.
        Is the volume of blood cultured still a significant factor in the diagnosis of bloodstream infections?.
        J Clin Microbiol. 2007; 45: 2765-2769
        • Patel R.
        • Vetter E.A.
        • Harmsen W.S.
        • et al.
        Optimized pathogen detection with 30- compared to 20-milliliter blood culture draws.
        J Clin Microbiol. 2011; 49: 4047-4051
        • O’Grady N.P.
        • Barie P.S.
        • Bartlett J.G.
        • et al.
        Guidelines for evaluation of new fever in critically ill adult patients: 2008 update from the American College of Critical Care Medicine and the Infectious Disease Society of America.
        Crit Care Med. 2008; 36: 1330-1349
        • Baron E.J.
        • Miller J.M.
        • Weinstein M.P.
        • et al.
        A guide to utilization of the microbiology laboratory for diagnosis of infectious diseases: 2013 recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM).
        Clin Infect Dis. 2013; 57: e22-e121
        • Schifman R.B.
        • Bachner P.
        • Howanitz P.J.
        Blood culture quality improvement: a College of American Pathologists Q-probes study involving 909 institutions and 289572 blood culture sets.
        Arch Pathol Lab Med. 1996; 120: 999-1002
        • Novis D.A.
        • Dale J.C.
        • Schifman R.B.
        • et al.
        Solitary blood cultures: a College of American Pathologists Q-Probes study of 132 778 blood culture sets in 333 small hospitals.
        Arch Pathol Lab Med. 2001; 125: 1290-1294
        • Lamy B.
        • Dargère S.
        • Arendrup M.C.
        • et al.
        How to optimize the use of blood cultures for the diagnosis of bloodstream infections? A state-of-the art.
        Front Microbiol. 2016; 7: 697
        • Schifman R.B.
        • Strand C.L.
        Blood culture Contamination Data Analysis and Critique. Q-Probes. College of American Pathologists, Chicago, IL1995: 1-19
        • Mermel L.A.
        • Maki D.G.
        Detection of bacteremia in adults: consequences of culturing an inadequate volume of blood.
        Ann Intern Med. 1993; 119: 270-272
        • Chang J.
        • Park J.S.
        • Park S.
        • et al.
        Impact of monitoring blood volume in the BD BACTECTM FX blood culture system: virtual volume versus actual volume.
        Diagn Microbiol Infect Dis. 2015; 81: 89-93
        • College of American Pathologists (CAP)
        College of American Pathologists Microbiology Checklist. CAP standard MIC.22640. Northfield, IL: CAP.
        • Coorevits L.
        • Van den Abeele A.M.
        Evaluation of the BD BACTEC FX blood volume monitoring system as a continuous quality improvement measure.
        Eur J Clin Microbiol Infect Dis. 2015; 34: 1459-1466
        • Cattoir L.
        • Claessens J.
        • Cartuyvels R.
        • et al.
        How to achieve accurate blood culture volumes: the BD BACTEC FX blood volume monitoring system as a measuring instrument and educational tool.
        Eur J Clin Microbiol Infect Dis. 2018; 37: 1621-1626
        • Lee S.
        • Kim S.
        Accuracy of BacT/Alert Virtuo for measuring blood volume for blood culture.
        Lab Med. 2019; 39: 590-592
        • Khare R.
        • Kothari T.
        • Castagnaro J.
        • et al.
        Active monitoring and feedback to improve blood culture fill volumes and positivity across a large integrated health system.
        Clin Infect Dis. 2020; 70: 262-268
        • Isenberg H.D.
        Clinical Microbiology Procedures Handbook.
        in: 3rd ed. ASM Press, Washington, DC2010 (Section 3.4.1, Aerobic bacteriology, blood cultures, general detection and interpretation)
        • Lemming L.
        • Holt H.M.
        • Petersen I.S.
        • et al.
        Bactec 9240 blood culture system: to preincubate at 35 degrees C or not?.
        Clin Microbiol Infect. 2004; 10: 1089-1091
        • Saito T.
        • Iinuma Y.
        • Takakura S.
        • et al.
        Delayed insertion of blood culture bottles into automated continuously monitoring blood culture systems increases the time from blood sample collection to the detection of microorganisms in bacteremic patients.
        J Infect Chemother. 2009; 15: 49-53
        • Janapatla R.P.
        • Yan J.J.
        • Chien M.L.
        • et al.
        Effect of overnight storage of blood culture bottles on bacterial detection time in the BACTEC 9240 blood culture system.
        J Microbiol Immunol Infect. 2010; 43: 126-132
        • Ronnberg C.
        • Mildh M.
        • Ullberg M.
        • et al.
        Transport time for blood culture bottles: underlying factors and its consequences.
        Diagn Microbiol Infect Dis. 2013; 76: 286-290
        • Kerremans J.J.
        • Van der Bij A.K.
        • Goessens W.
        • et al.
        Immediate incubation of blood cultures outside routine laboratory hours of operation accelerates antibiotic switching.
        J Clin Microbiol. 2009; 47: 3520-3523
        • Lee D.H.
        • Koh E.H.
        • Choi S.R.
        • et al.
        Growth dynamics of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa as a function of time to detection in BacT/Alert 3D blood culture bottles with various preincubation conditions.
        Ann Lab Med. 2013; 33: 406-409
        • Sautter R.L.
        • Bills A.R.
        • Lang D.L.
        • et al.
        Effects of delayed-entry conditions on the recovery and detection of microorganisms from BacT/ALERT and BACTEC blood culture bottles.
        J Clin Microbiol. 2006; 44: 1245-1249
        • Morton B.
        • Nagaraja S.
        • Collins A.
        • et al.
        A retrospective evaluation of critical care blood culture yield—do support services contribute to the “weekend effect”?.
        PLoS One. 2015; 10e0141361
        • Venturelli C.
        • Righi E.
        • Borsari L.
        • et al.
        Impact of preanalytical time on the recovery of pathogens from blood cultures: results from a large retrospective survey.
        PLoS One. 2017; 12e0169466
        • Martinez R.M.
        Remote technical review of blood culture Gram stains at a large integrated healthcare network.
        J App Lab Med. 2019; 3: 733-734
        • Horvath L.L.
        • George B.J.
        • Murray C.K.
        • et al.
        Direct comparison of the BACTEC 9240 and BacT/ALERT 3D automated blood culture systems for Candida growth detection.
        J Clin Microbiol. 2004; 42: 115-118
        • Horvath L.L.
        • George B.J.
        • Hospenthal D.R.
        Detection of fifteen species of Candida in an automated blood culture system.
        J Clin Microbiol. 2007; 45: 3062-3064
        • Ben-Ami R.
        • Weinberger M.
        • Orni-Wasserlauff R.
        • et al.
        Time to blood culture positivity as a marker for catheter-related candidemia.
        J Clin Microbiol. 2008; 46: 2222-2226
        • Wilson M.L.
        • Mirrett S.
        • Reller L.B.
        • et al.
        Recovery of clinically important microorganisms from the BacT/Alert blood culture system does not require testing for seven days.
        Diagn Microbiol Infect Dis. 1993; 16: 31-34
        • Baron E.J.
        • Scott J.D.
        • Tompkins L.S.
        Prolonged incubation and extensive subculturing do not increase recovery of clinically significant microorganisms from standard automated blood cultures.
        Clin Infect Dis. 2005; 41: 1677-1680
        • Petti C.A.
        • Bhally H.S.
        • Weinstein M.P.
        • et al.
        Utility of extended blood culture incubation for isolation of Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella organisms: a retrospective multicenter evaluation.
        J Clin Microbiol. 2006; 44: 257-259
        • Morris A.J.
        • Taylor S.L.
        • Ikram R.
        • et al.
        Clinical audit for the need to process blood cultures signalling positive after hours.
        Pathology. 2007; 39: 531-535
        • Murdoch D.A.
        • Koerner R.J.
        • Speirs G.E.
        • et al.
        Do blood cultures need continuous monitoring so that clinical action can be taken outside normal working hours?.
        J Clin Pathol. 1995; 48: 1067-1068
        • Fitzpatrick F.
        • Turley M.
        • Humphreys H.
        • et al.
        An after-hours clinical liaison blood culture service – is it worth it?.
        Clin Microbiol Infect. 2004; 10: 917-921
        • Munson E.L.
        • Diekema D.J.
        • Beekmann S.E.
        • et al.
        Detection and treatment of bloodstream infection: laboratory reporting and antimicrobial management.
        J Clin Microbiol. 2003; 41: 495-497
        • Savinelli T.
        • Parenteau S.
        • Mermel L.A.
        What happens when automated blood culture instrument detect growth but there are no technologists in the microbiology laboratory.
        Diagn Microbiol Infect Dis. 2004; 48: 173-174
        • Dargere S.
        • Cormier H.
        • Verdon R.
        Contaminants in blood cultures: importance, implications, interpretation and prevention.
        Clin Microbiol Infect. 2018; 24: 964-969
        • Richter S.S.
        • Beekmann S.E.
        • Croco J.L.
        • et al.
        Minimizing the workup of blood culture contaminants: implementation and evaluation of a laboratory-based algorithm.
        J Clin Microbiol. 2002; 40: 2437-2444
        • Bates D.W.
        • Goldman L.
        • Lee T.H.
        Contaminant blood cultures and resource utilization. The true consequences of false-positive results.
        JAMA. 1991; 265: 365-369
        • Weinstein M.P.
        • Towns M.L.
        • Quartey S.M.
        • et al.
        The clinical significance of positive blood cultures in the 1990s: a prospective comprehensive evaluation of the microbiology, epidemiology, and outcome of bacteremia and fungemia in adults.
        Clin Infect Dis. 1997; 24: 584-602
        • Schifman R.B.
        • Strand C.L.
        • Meier F.A.
        • et al.
        Blood culture contamination: a College of American Pathologists Q-Probes study involving 640 institutions and 497134 specimens from adult patients.
        Arch Pathol Lab Med. 1998; 122: 216-221
        • Jonasson E.
        • Matuschek E.
        • Kahlmeter G.
        The EUCAST rapid disc diffusion method for antimicrobial susceptibility testing directly from positive blood culture bottles.
        J Antimicrob Chemother. 2020; 75: 968-978
      2. EUCAST. Methodology - EUCAST rapid antimicrobial susceptibility testing (RAST) directly from positive blood culture bottles.Version 1.1,2019 (Cited 29 Jul 2020)
        • Chandrasekaran S.
        • Abbott A.
        • Campeau S.
        • et al.
        Direct-from-blood culture disk diffusion to determine antimicrobial susceptibility of gram-negative bacteria: preliminary report from the clinical and laboratory standards Institute methods development and standardization working group.
        J Clin Microbiol. 2018; 56: e01678-e01717
        • Lamy B.
        Towards an improved diagnosis of bloodstream infection: promises and hurdles.
        Clin Microbiol Infect. 2018; 24: 933-934
        • Doern G.V.
        • Carroll K.C.
        • Diekema D.J.
        • et al.
        A comprehensive update on the problem of blood culture contamination and a discussion of methods for addressing the problem.
        Clin Microbiol Rev. 2019; 33: e00009-e00019
        • Gilligan P.
        Blood culture contamination: a clinical and financial burden.
        Infect Control Hosp Epidemiol. 2013; 34: 1-2
        • van der Heijden Y.F.
        • Miller G.
        • Wright P.W.
        • et al.
        Clinical impact of blood cultures contaminated with coagulase-negative staphylococci at an academic medical center.
        Infect Control Hosp Epidemiol. 2011; 32: 623-625
        • Gander R.M.
        • Byrd L.
        • DeCrescenzo M.
        • et al.
        Impact of blood cultures drawn by phlebotomy on contamination rates and health care costs in a hospital emergency department.
        J Clin Microbiol. 2009; 47: 1021-1024
        • Alahmadi Y.M.
        • Aldeyab M.A.
        • McElnay J.C.
        • et al.
        Clinical and economic impact of contaminated blood cultures within the hospital setting.
        J Hosp Infect. 2011; 77: 233-236
        • Souvenir D.
        • Anderson Jr., D.E.
        • Palpant S.
        • et al.
        Blood cultures positive for coagulase-negative staphylococci: antisepsis, pseudobacteremia, and therapy of patients.
        J Clin Microbiol. 1998; 36: 1923-1926
        • Lee C.C.
        • Lin W.J.
        • Shih H.I.
        • et al.
        Clinical significance of potential contaminants in blood cultures among patients in a medical center.
        J Microbiol Immunol Infect. 2007; 40: 438-444
        • Salcedo D.T.
        • Powell E.A.
        • Smulian A.G.
        • et al.
        Actual clinical practice related to contaminated blood cultures may limit the cost savings associated with interventions to reduce contamination rates.
        J Clin Microbiol. 2020; 58: e01796-e01819
        • Bekeris L.G.
        • Tworek J.A.
        • Walsh M.K.
        • et al.
        Trends in blood culture contamination: a College of American Pathologists Q-Tracks Study of 356 institutions.
        Arch Pathol Lab Med. 2005; 129: 1222-1225
        • Overton K.
        • Gulholm T.
        • Post J.J.
        • et al.
        Impact of contaminated blood cultures on health care costs and resource utilisation.
        Aust J Med Sci. 2016; 37: 100-107
        • Eskira S.
        • Gilad J.
        • Sclaeffer P.
        • et al.
        Reduction of blood culture contamination rate by an educational intervention.
        Clin Microbiol Infect. 2006; 12: 818-821
        • Robert R.R.
        Reducing blood-culture contamination through an education program.
        J Infus Nurs. 2011; 34: 49-54
        • Hopkins K.
        • Huynh S.
        • McNary C.
        • et al.
        Reducing blood culture contamination rates: a systematic approach to improving quality of care.
        Am J Infect Control. 2013; 41: 1272-1274
        • Murphy T.
        • Maile D.
        • Barsch T.
        • et al.
        Investigating the impact of blood culture bundles on the incidence of blood culture contamination rates.
        J Infus Nurs. 2014; 37: 205-209
        • Hall K.K.
        • Lyman J.A.
        Updated review of blood culture contamination.
        Clin Microbiol Rev. 2006; 19: 788-802
        • Weinstein M.P.
        Blood culture contamination: persisting problems and partial progress.
        J Clin Microbiol. 2003; 41: 2275-2278
        • Graham M.
        • Walker D.A.
        • Haremza E.
        • et al.
        RCPAQAP audit of antimicrobial reporting in Australian and New Zealand laboratories: opportunities for laboratory contribution to antimicrobial stewardship.
        J Antimicrob Chemother. 2016; 74: 251-255
        • Royal College of Pathologists of Australasia (RCPA)
        Selective reporting of antimicrobials.
        Guideline, 2019 (1st ed. Cited 29 Jul 2020)
        • Clinical and Laboratory Standards Institute (CLSI)
        CLSI document M100. 30th ed. Performance Standards for Antimicrobial Susceptibility Testing. CLSI, Wayne, PA2020
        • Pulcini C.
        • Tebano G.
        • Mutters N.T.
        • et al.
        Selective reporting of antibiotic susceptibility test results in European countries: an ESCMID cross-sectional survey.
        Int J Antimicrob Agents. 2017; 49: 162-166
        • Langford B.J.
        • Seah J.
        • Chan A.
        • et al.
        Antimicrobial stewardship in the microbiology laboratory: impact of selective susceptibility reporting on ciprofloxacin utilization and susceptibility of Gram-negative isolates to ciprofloxacin in a hospital setting.
        J Clin Microbiol. 2016; 54: 2343-2347
        • Coupat C.
        • Pradier C.
        • Degand N.
        • et al.
        Selective reporting of antibiotic susceptibility data improves the appropriateness of intended antibiotic prescriptions in urinary tract infections: a case-vignette randomised study.
        Eur J Clin Microbiol Infect Dis. 2013; 32: 627-636
        • Tan T.Y.
        • McNulty C.
        • Charlett A.
        • et al.
        Laboratory antibiotic susceptibility reporting and antibiotic prescribing in general practice.
        J Antimicrob Chemother. 2003; 51: 379-384
        • McNulty C.A.
        • Lasseter G.M.
        • Charlett A.
        • et al.
        Does antibiotic susceptibility reporting influence primary care prescribing in urinary tract infection and other infections?.
        J Antimicrob Chemother. 2011; 66: 1396-1404
        • National Pathology Accreditation Advisory Council (NPAAC)
        3rd ed. Requirements for Medical Pathology Services. NPAAC, Canberra2018
        • International Accreditation New Zealand (IANZ)
        3rd ed. Specific Criteria for Accreditation: Medical Testing. IANZ, Auckland2019
        • International Organization for Standardization
        3rd ed. ISO15189 Medical Laboratories – Requirements for Quality and Competence. ISO, Geneva2012
        • Pavlovsky M.
        • Press J.
        • Peled N.
        • et al.
        Blood culture contamination in pediatric patients: young children and young doctors.
        Pediatr Infect Dis J. 2006; 25: 611-614
        • Hall R.T.
        • Domenico H.J.
        • Self W.H.
        • et al.
        Reducing the blood culture contamination rate in a pediatric Emergency Department and subsequent cost savings.
        Pediatrics. 2013; 131: 292-297