title: Candida colonization as a risk marker for invasive candidiasis in mixed medical-surgical intensive care units: development and evaluation of a simple, standard protocol.
abstract: Colonization with Candida species is an independent risk factor for invasive candidiasis (IC), but the minimum and most practicable parameters for prediction of IC have not been optimized. We evaluated Candida colonization in a prospective cohort of 6,015 nonneutropenic, critically ill patients. Throat, perineum, and urine were sampled 72 h post-intensive care unit (ICU) admission and twice weekly until discharge or death. Specimens were cultured onto chromogenic agar, and a subset underwent molecular characterization. Sixty-three (86%) patients who developed IC were colonized prior to infection; 61 (97%) tested positive within the first two time points. The median time from colonization to IC was 7 days (range, 0 to 35). Colonization at any site was predictive of IC, with the risk of infection highest for urine colonization (relative risk [RR]=2.25) but with the sensitivity highest (98%) for throat and/or perineum colonization. Colonization of ≥2 sites and heavy colonization of ≥1 site were significant independent risk factors for IC (RR=2.25 and RR=3.7, respectively), increasing specificity to 71% to 74% but decreasing sensitivity to 48% to 58%. Molecular testing would have prompted a resistance-driven decision to switch from fluconazole treatment in only 11% of patients infected with C. glabrata, based upon species-level identification alone. Positive predictive values (PPVs) were low (2% to 4%) and negative predictive values (NPVs) high (99% to 100%) regardless of which parameters were applied. In the Australian ICU setting, culture of throat and perineum within the first two time points after ICU admission captures 84% (61/73 patients) of subsequent IC cases. These optimized parameters, in combination with clinical risk factors, should strengthen development of a setting-specific risk-predictive model for IC.
authors: Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, University of Sydney, Westmead Hospital, Westmead, New South Wales, Australia Anna.Lau@nih.gov.
authors: Anna F
authors: AF
authors: Lau
authors: Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, University of Sydney, Westmead Hospital, Westmead, New South Wales, Australia.
authors: Masrura
authors: M
authors: Kabir
authors: Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, University of Sydney, Westmead Hospital, Westmead, New South Wales, Australia Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR-Pathology West, Westmead Hospital, New South Wales, Australia.
authors: Sharon C-A
authors: SC
authors: Chen
authors: Infection Management Services, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
authors: E Geoffrey
authors: EG
authors: Playford
authors: Department of Microbiology and Infectious Diseases, St Vincent's Hospital, Darlinghurst, New South Wales, Australia.
authors: Deborah J
authors: DJ
authors: Marriott
authors: Psychology Department, Macquarie University, North Ryde, New South Wales, Australia.
authors: Michael
authors: M
authors: Jones
authors: Department of Intensive Care Medicine, Royal Brisbane and Women's Hospital, The University of Queensland, Herston, Queensland, Australia.
authors: Jeffrey
authors: J
authors: Lipman
authors: Victorian Infectious Diseases Service, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia.
authors: Emma
authors: E
authors: McBryde
authors: Department of Microbiology and Infectious Diseases, Concord Hospital, Concord, New South Wales, Australia.
authors: Thomas
authors: T
authors: Gottlieb
authors: Department of Intensive Care Medicine, Concord Repatriation General Hospital, Concord, New South Wales, Australia.
authors: Winston
authors: W
authors: Cheung
authors: Department of Intensive Care Medicine, Nepean Hospital, University of Sydney, Penrith, New South Wales, Australia.
authors: Ian
authors: I
authors: Seppelt
authors: Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, University of Sydney, Westmead Hospital, Westmead, New South Wales, Australia Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Westmead, New South Wales, Australia.
authors: Jonathan
authors: J
authors: Iredell
authors: Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute, University of Sydney, Westmead Hospital, Westmead, New South Wales, Australia Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Westmead, New South Wales, Australia.
authors: Tania C
authors: TC
authors: Sorrell
mesh_terms: D002175:Candida / Q000302:isolation & purification*; D058365:Candidiasis, Invasive / Q000175:diagnosis*; D002353:Carrier State / Q000175:diagnosis*; D016638:Critical Illness; D003955:Diagnostic Tests, Routine / Q000379:methods / Q000592:standards*; D006801:Humans; D007362:Intensive Care Units; D008828:Microbiological Techniques / Q000379:methods / Q000592:standards*; D010502:Perineum / Q000382:microbiology; D010614:Pharynx / Q000382:microbiology; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D014556:Urine / Q000382:microbiology