David FerreiraFrederic GrenouilletGilles BlascoEmmanuel SamainThierry HenonAlain DussaucyLaurence MillonMariette MercierSebastien Pili-Floury

Outcomes associated with routine systemicantifungal therapy in critically ill patientswith Candida colonization

Received: 16 December 2014Accepted: 30 March 2015Published online: 18 April 2015� Springer-Verlag Berlin Heidelberg andESICM 2015

Take-home message: Preemptiveantifungal approach based on systematicscreening of Candida colonization during a8-year period, induced an increase in C.glabrata colonization in surgical ICUpatients, without significant shift ofcolonization to other Candida spp.

Electronic supplementary materialThe online version of this article(doi:10.1007/s00134-015-3791-4) containssupplementary material, which is availableto authorized users.

D. Ferreira � G. Blasco � E. Samain �S. Pili-Floury ())Department of Anesthesiology andIntensive Care Medicine, UniversityHospital of Besancon, 25000 Besancon,Francee-mail: spilifloury@orange.frTel.: ?33381668579

F. Grenouillet � L. MillonDepartment of Parasitology-Mycology,University Hospital of Besancon, 25000Besancon, France

F. Grenouillet � L. MillonUMR CNRS 6249, University of FrancheComte, 25000 Besancon, France

E. Samain � S. Pili-FlouryEA 3920, INSERM SFR 4232, Universityof Franche-Comte, 25000 Besancon, France

T. HenonDepartment of Pharmacy, UniversityHospital of Besancon, 25000 Besancon,France

A. DussaucyDepartment of Medical InformationSystems, University Hospital, 25000Besancon, France

M. MercierDepartment of Biostatistics, UniversityHospital of Besancon, 25000 Besancon,France

M. MercierEA 3181, INSERM SFR 4232, Universityof Franche-Comte, 25000 Besancon, France

Abstract Purpose: To assess theevolution of patient deep colonizationby Candida spp. in a surgical ICUover an 8-year period. Meth-ods: This retrospective,observational study included all pa-tients hospitalized for more than2 days in a surgical and trauma ICUof a university hospital, from 2005 to2012. Mycological samples weremonitored weekly from five sites(oropharyngeal, rectal, gastric, tra-cheal and urinary). Preemptivefluconazole therapy was started inpatients highly colonized with Can-dida albicans. The evolution inCandida spp. involved in the deepcolonization sites distribution overthe study period (main outcomemeasure, trend chi-square and time-

series analysis), antifungal consump-tion, ICU-acquired candidemia andmortality were determined. Re-sults: Among the 3029patients with ICU stay[48 h, 2651had at least one set of mycologicalsampling. Thirty percent of the31,171 samples were positive toCandida spp. Caspofungin consump-tion increased over the years, whereasfluconazole consumption decreased.No trend in C. albicans colonizationwas observed, after adjusting oncolonization risk-factors. A sig-nificant increase of acquired C.glabrata colonization was observed,whereas the clearing of C.parapsilosis colonization significantlydecreased. No significant shift ofcolonization to other Candida spp.and mortality was observed. Conclu-sions: Preemptive strategy ofantifungal drug prescriptions inhighly colonized ICU patients in-duced an increase in C. glabratacolonization without significant shiftof colonization to other Candida spp.in surgical ICU patients. However,the potential detrimental impact offluconazole on Candida ecology inICU and/or on Candida susceptibilityto antifungal drugs should be con-sidered, and deserves further studies.

Keywords Candida colonization �Antifungal drug � Drug utilization

Intensive Care Med (2015) 41:1077–1088DOI 10.1007/s00134-015-3791-4 ORIGINAL

Introduction

Critically ill patients are at risk of opportunistic invasivefungal infections (IFI), mainly caused by Candida spp.[1]. These infections carry a high risk of morbidity andmortality for ICU patients, in part because of the delay inIFI diagnosis and/or of suboptimal initial antifungaltreatment [2–4]. This has led to an increasing use ofempirical curative antifungal therapy in cases of IFIsuspicion [5]. Pharmacotherapy of antifungal agent hasbeen dramatically modified in the last decade by theavailability of new azoles and echinocandins, activeagainst naturally resistant fungal species, and better tol-erated than former antifungal drugs. Fluconazole, andthen caspofungin since the publication of InfectiousDiseases Society of America (IDSA) guidelines in 2009,are now widely used as first-line treatment in suspectedIFI in ICU patients [6].

Candida colonization at one or more deep anatomicalsites frequently precedes bloodstream infection in non-neutropenic patients, and the rate of colonized patients inICU increases as exposure to risk factors is prolonged [1, 7,8]. In this regard, Pittet et al. [9] have shown a relationshipbetween the intensity of fungal colonization and the risk ofIFI in ICU patients. Several clinical predictive tools, in-cluding regular screening of anatomical colonization sites,Candida-score, or biomarkers such as beta-glucan, havebeen proposed for the early risk assessment of IFI, either inall ICU patients or in selected high-IFI risk patients [8, 10].Despite improved knowledge of the pathophysiology ofIFI, indication of early antifungal therapy remains a subjectof debate and no high-level recommendation regardingmanagement of highly colonized non-immunocompro-mized patients are yet available [11, 12]. Several studies,including one conducted at our surgical/trauma ICU, havereported the benefit of triazole-based antifungal preemptiveor prophylactic therapy in colonized non-immunocom-promized ICU patients to reduce IFI incidence [13–18].Others studies failed to demonstrate a beneficial effect ofempirical fluconazole or caspofungin therapy in selectedIFI high-risk patients [19–22]. On the other hand, pre-emptive or prophylactic strategiesmay promote emergenceof Candida spp. with antifungal drugs reduced suscepti-bility and lead to an increase use of antifungals in ICU [23].In this regard, Azoulay et al. [24] have shown in a 1-daycross-sectional cohort study, that 7.5 % of ICU patientswere given systemic antifungal therapy, two-third of themwith no documented IFI.

The impact of such a wide use of antifungal therapy inICU on Candida spp. epidemiology and/or susceptibilityremains a subject of concern. A shift in the fungal epi-demiology towards more resistant non-albicans species,including C. glabrata, has been reported in patients re-ceiving azole during their ICU stay [25, 26]. However,contradictory data have been reported by others, and

several authors pointed out the need for further investi-gation to assess the risk of alteration in Candida spp.ecology when preemptive or prophylactic antifungaltherapies are used in ICU [18, 27, 28].

Candida colonization-based preemptive antifungalprescriptions are ongoing since 2000 in our surgical ICU[13]. Thus, antifungal use increased significantly duringthe last decades with an unequivocal increase of echino-candin use in the last 5–6 years, succeeding a period ofextended fluconazole use. This prompted us to design thisstudy to assess the evolution of the colonization byCandida spp. in our ICU over an 8-year period.

Methods

This retrospective, observational study was carried out inthe adult surgical ICU of a University Hospital givingtertiary care in France, between January 1 2005 and De-cember 31 2012. All patients admitted for the first time inthe ICU were included. Patient case-mix included traumaand surgical patients. Patients were excluded from theanalysis if their ICU stay was less than 2 days.

The study was conducted in accordance withStrengthening the Reporting of Observational studies inEpidemiology (STROBE) statement (www.strobe-statement.org) and was approved by the InstitutionalReview Board of the University Hospital of Besancon(Chairperson: Prof E Haffen; study approval: Prof EToussirot, IRB #13-08) on March 8 2013.

For the purpose of this work, a study database wascreated by the aggregation of data from three electronicdatabases, set up prospectively since 2002, using the singleidentification number attributed to each patient upon hisadmittance to our Institution.Quality of datawas controlledfor 50 randomly selected files by checking the lack of dis-cordance between the database and patient medical files forthe following parameters: patient ID, age, sex, main diag-nosis, duration of mechanical ventilation, results ofmycological screening, and antifungal treatment. Datawere then anonymized before analysis by generating atrandom a study-specific number for each patient.

Demographic data of patients admitted in the ICU duringthe study period, including age, sex, surgical or trauma case-mix, Simplified Acute Physiology Score (SAPS) 2, me-chanical ventilation, date of ICU admission, duration of ICUstay, and mortality in ICU were extracted from the Institu-tional Department of Medical Information database.

Mycological data

Database from the Department of Mycology, aggregatedthe results of all Candida specimens collected from ICU

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patients throughout the study period. A mycologicalscreening was performed on every patient admitted to theICU, first at admittance and then once a week thereafteruntil discharge from the ICU [13]. Screening included 5biological samples: gastric and tracheal aspirates, urinecollection, oropharyngeal and rectal swabs. Specimenswere cultured on CHROMagar medium (Becton-Dickin-son, Le Pont de Claix, France). Yeast colonies werecounted after 2-day incubation at 30 �C and identifiedaccording to the specific color of colonies (C. albicans);the ID 32C system (BioMerieux, Marcy l’Etoile, France)was used for other yeast species. Results were consideredas positive when at least one colony of Candida spp. wasfound on a culture plate. Limits of detection were 1 col-ony-forming unit (CFU) for swabs, 100 CFU/mL forgastric juice and urine, and 104 CFU/mL for trachealaspirates. Results were rated as highly positive when theyreached the threshold of 100 CFU for rectal and oropha-ryngeal swabs and 105 CFU/mL for gastric, trachealaspirate, and urine [9]. Colonization index (CI: ratio ofthe number of positive samples to the total number ofsamples) and corrected colonization index (CCI: ratio ofhighly positive samples to the total number of samplescultured) were calculated at admittance and once a weekfor each patient [9]. At least three samples were necessaryto take into account colonization indexes.

Antifungal drugs use

Preemptive antifungal drugs strategy in our surgical ICUwas based on a protocol described by Piarroux et al. [13]implemented in 2000, and slightly modified in 2004:briefly, an early intravenous fluconazole therapy wasstarted in C. albicans highly colonized patients. No pre-emptive treatment was given to patients colonized withnon-albicans Candida spp. In cases of suspected IFI,empirical therapy was started after blood cultures, usingeither fluconazole or caspofungin from 2005 to 2008, andcaspofungin from 2009 to 2012. Antifungal drug wassecondarily adapted to antifungal susceptibility in con-firmed candidemia.

Main outcome measure

Evolution over years of epidemiology of the followingCandida spp. involved in patient colonization was themain outcome measure: C. albicans, C. glabrata, C.krusei, C. parapsilosis, C. guilliermondi, C. norvegensis,C. inconspicua, C. tropicalis, and C. kefyr. In order tomake the results clearer, the four later fungal species,infrequently involved in patient colonization, were ag-gregated into two groups according to their usualantifungal susceptibility profile, as follows: Candida spp.group 1 included C. norvegensis and C. inconspicua,

because of their natural resistance to fluconazole, andCandida spp. group 2 included C. tropicalis and C. kefyr.Results regarding C. guilliermondi, not identified in anypatient of our series, were discarded from the analysis.

Antifungal drug use data were extracted from theHospital Pharmacy Department database, collecting allorders related to certain selected drugs. The consumptionof plain and liposomal amphotericin B, caspofungin andvoriconazole for the whole study period, and for flu-conazole after 2007 was recorded for each patient.According to Guidelines for ATC classification and de-fined daily doses (DDD) assignment, individualantifungal doses were converted in DDD per 1000 hos-pital days (DDDs/1000HD) [29]. As orders forfluconazole were added to the database only after 2007,DDD for this agent between 2005 and 2007 were ex-trapolated from ICU global fluconazole consumption datagiven by the Hospital Pharmacy Department. The DDDswere 35 mg for amphotericin B, 50 mg for caspofungin,200 mg for fluconazole and 400 mg for voriconazole. Useof itraconazole, posaconazole, 5-fluorocytosine, mica-fungin and anidulafungin in our ICU was very low duringthe study period and therefore was not considered in theanalysis.

The evolution over years of the following parameterswas analyzed: (1) number of candidemias acquired atleast 48 h after ICU admission up to 3 weeks followingICU discharge; (2) percentage of patients with a negativeor positive colonization index before onset of candidemia;(3) Candida spp. distribution of fungemia; (4) mortalityduring ICU stay. Minimal inhibitory concentrations offluconazole, voriconazole, caspofungin and amphotericinwere measured for each Candida spp. involved in ICUacquired candidemia to determine the resistance profile ofthe strain.

Statistical analysis

Results are expressed as mean [standard deviation (SD)]or median (interquartile) for quantitative variables asappropriate, and as frequency and percentage forqualitative variables. The statistical unit in the study wasthe patient. Patients’ characteristics and fungi ecologywere described separately for every year of the studyperiod.

Categorical variables were compared by the chi-square test or Fisher’s exact test. Student’s t test was usedto compare normally distributed continuous variables, andthe Kruskal–Wallis test was used to analyze non-normallydistributed variables. Comparison of data over years, wasperformed using a trend chi-square test or linear regres-sion test for qualitative or quantitative variables,respectively. A stepwise logistic regression was used todetermine whether colonization to either Candida spp., C.albicans, C. non-albicans spp. or C. glabrata was

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influenced by the period after adjusting for the followingconfusion variables: age, SAPS-2[40, parenteral nutri-tion, surgery before ICU admission and cancer. Thevariable period was forced into the multivariate model.

Candida colonization, C. glabrata colonization duringICU stay, acquisition for C. glabrata colonization andmortality weighted by the number of hospitalized patientswere tested for stationarity using an augmented Dickey–Fuller (ADF) test for unit root (p\ 0.05 meaning station-arity). Autoregressive (AR) andmoving average (MA)withnonseasonal models were used for the analysis. The timeunit was the month. Results of the different models werecompared using Bayesian Information Criteria (BIC). Themodelwith the lowestBICwas kept and the adequacy of thebest-fit model was tested by examining the autocorrelationfunction of the residuals. Ljung-Box test statisticswere alsoused. The model was ignored if the Ljung-Box Q statisticsgave a significant p value.When autoregressionwas nil, theconstant estimate was the mean of the variable and therewas no change during the study period. p values were two-tailed. Statistical analysis was performed by M.M. (PhD inbiostatistics) and D.F., using SAS 9.3 software (SAS In-stitute, Cary, NC, USA). Statistical significance was set atp = 0.05.

Results

Demographic data

Among the 3563 patients admitted for the first time be-tween 2005 and 2012 at our ICU (42,502 days ofhospitalization), 534 had a length of stay less than 2 days.The number of patients admitted per year was higher after2010 as the ICU capacity was increased from 15 to 20beds from May 2010. Patient characteristics did not differsignificantly over years throughout the study, except for asignificant increase in both SAPS 2 value and the per-centage of surgical patients (Table 1).

Mycological screening

The results of mycological follow up performed in 2527ICU patients hospitalized during the study period ac-cording to their CI are given in Fig. 1. Altogether, 31,171mycological samples were analyzed, among which 9343(30 %) were positive for Candida spp. Fig. 1a describesthe results of the screening carried out on patient ICU atadmittance. Complete mycological data were availablefor 2617 patients. A negative CI (\0.5) was observed in71 % of the patients hospitalized in the ICU. Among the666 patients with a CI C 0.5, C. albicans, C. krusei, andC. glabrata were present in 84.8, 8.4 and 26.7 % of thecases, respectively. T

ab

le1ICU

patients

dem

ographic

databetween2005and2012

Studyperiod

Allpatients

pvalue

2005

2006

2007

2008

2009

2010

2011

2012

2005–2012

No.ofpatients

397

376

415

418

418

470

550

519

3563

Age,

years

56(40;70)

57(41;69)

58(42;72)

56(42;69)

59(43;72)

58(45;71)

59(43;70)

60(43;69)

58(43;70)

0.56

Sex

malea

229(58)

249(66)

269(65)

260(62)

263(63)

294(63)

357(65)

328(63)

2249(63)

0.37

SAPS-2

35(25;49)

36(26;49)

43(29;57)

42(30;57)

42(30;56)

41(31;56)

42(30;56)

43(32;57)

41(30;55)

\0.0001

ICU

stay,days

5(2;18)

5(2;18)

4(2;14)

6(2;15)

5(2;14)

6(2;16)

6(2;15)

5(2;12)

5(2;15)

0.08

Surgical

patientsa

224(56)

243(65)

276(67)

295(71)

307(73)

341(73)

401(73)

402(77)

2489(70)

\.0001

Traumapatientsa

57(14)

52(13)

50(12)

58(13)

66(15)

76(16)

91(16)

65(12)

515(14)

0.44

Mechanical

ventilationa

371(93)

365(97)

394(95)

394(94)

392(94)

445(95)

513(93)

484(93)

3358(94)

0.12

ICU

mortalitya

107(27)

79(21)

99(24)

100(24)

94(22)

91(19)

120(22)

117(23)

807(23)

0.11

Resultsaregiven

asmedian(interquartile)

SAPSsimplified

acute

physiologyscore

aResultsaregiven

asn(%

)

1080

Figure 1b describes the results of the last mycologicalscreening carried out during the patient’s ICU stay. Datawere not available for 993 patients, because of either anICU stay below 1 week or a mycological screening notdone or incomplete. Among patients with a negative CIupon admission, 69 % remained negative throughout theirstay and 31 % became positive. Of the patients with apositive CI at admittance, 33 % were negative afterwards,and 67 % remained positive throughout their ICU stay. Inboth cases, C. albicans, C. glabrata and C. krusei werethe most represented species.

Antifungal consumption

Antifungal consumption, expressed in DDDs/1000HD, isgiven in Table 2. Caspofungin and fluconazole were thetwo antifungal drugs commonly used in the study period.There was a significant increase in the average con-sumption of caspofungin over the years, whereas average

consumption of fluconazole decreased. The use of am-photericin or voriconazole therapies was scarce andvaried widely from one year to another, as they weremainly given to a few patients to treat invasive mu-cormycosis or aspergillosis, respectively.

Evolution of fungal colonization over the study period

The percentage of patients with a CI[ 0.5 was not sig-nificantly altered over the years throughout the study(Table 3). No significant change over the years in thepercentage of Candida spp. in specimens sampled uponpatient admission in ICU was observed (Table 3).

The evolution during the study period of Candidaspp. involved in patient colonization over the years isgiven in Fig. 2. Figure 2a describes the evolution inpatients with a positive colonization upon admission thatremained positive at discharge from ICU. Figure 2bdescribes the evolution in patients colonized during ICU

Fig. 1 Schematic representation of mycological screening per-formed in patients during their ICU stay. a The screening carriedout on patient admittance in ICU. In patients with a colonization

index[0.5, the percentage is[100 % because multi-Candida spp.colonization was observed in some patients. b Result ofs myco-logical screening done weekly during the patient’s ICU stay

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stay and Fig. 2c those patients with a positivecolonization upon admission and negative at dischargefor the ICU. The distribution of Candida spp. responsi-ble for acquired colonization during their ICU stayvaried widely from one year to another. Two significanttrends were observed during the 8 years of the study.First, a significant increase in acquired colonization withC. glabrata occurred. We also observed a significant

decrease in the clearing of C. parapsilosis colonizationduring ICU stay (p = 0.001). In multivariate analysis,SAPS-2 C40 was independently associated with Can-dida spp. colonization [OR (95 % CI) = 1.23(1.05–1.43); p = 0.007] and non-albicans Candidacolonization [1.71 (1.31–2.19); p = 0.006], and cancerwas also independently associated with non-albi-cans Candida colonization [1.39 (1.04–1.84); p = 0.03].

Table 2 Main antifungal drugs prescribed to patients between 2005 and 2012

Drug Study period All patients

2005 2006 2007 2008 2009 2010 2011 2012 2005–2012

Total no. of patients 397 376 415 418 418 470 550 519 3563Amphotericin Ba No. patients 0 1 1 1 2 1 0 5 11

DDDs/1000HD 0 5.1 8.7 72.7 96.9 24.0 0 89.9 297.3Caspofungina No. patients 4 13 16 16 47 47 64 91 298

DDDs/1000HD 10.3 30.9 30.7 32.9 121.0 64.9 86.4 171.0 548.1Fluconazoleb No. patients na na na 74 60 64 64 59 [321

DDDs/1000HD 310.0 347.8 375.5 274.6 260.0 247.5 269.3 243.2 2327.9Voriconazolea No. patients 6 3 1 3 2 2 4 3 24

DDDs/1000HD 21.6 6.0 2.2 3.5 8.1 8.8 6.6 2.2 59

The number of patients who received the treatment and the defineddaily doses per 1000 hospital days (DDDs/1000HD, definition in‘‘Methods’’) are given for each of the four main antifungal drugsna not availablea Includes amphotericin B and liposomal amphotericin B

b Data are extracted from individual antifungals drug use database,except for fluconazole from 2005 to 2008, where data are from ICUantifungal billing

Table 3 Epidemiology of fungal colonization and candidemia between 2005 and 2012

Study period All patients p

2005 2006 2007 2008 2009 2010 2011 2012 2005–2012

No. of patients 397 376 415 418 418 470 550 519 3563Candida colonizationa

Mycological screening, yes (n) 282 262 323 290 280 343 434 437 2651 \0.0001C1 positive sample site (%) 73 67 69 71 66 62 62 63 63 0.0004Colonization index C0.5 (%) 21 28 25 26 29 29 19 25 26 0.7941Corrected colonization index C0.4 (%) 13 16 16 20 19 17 13 14 16 0.4868Epidemiology of mycological screeningC. albicans (%) 57 57 55 61 55 53 51 53 53 0.0457C. glabrata (%) 15 10 11 15 9 8 11 11 11 0.0688C. krusei (%) 5 3 5 4 6 3 5 3 3 0.1376C. parapsilosis (%) 5 2 3 2 3 2 1 2 2 0.0032Group Candida spp. 1 (%) 2 2 3 4 2 1 3 2 2 0.4654Group Candida spp. 2 (%) 7 10 11 10 7 7 7 11 9 0.9656

Candidemiab

No. of patients 3 4 1 3 2 5 3 2 23Epidemiology of candidemiaC. albicans (n) 1 2 2 2 2 1 10C. glabrata (n) 1 1 1 3C. krusei (n) 0C. parapsilosis (n) 2 1 1 3 7Group Candida spp. 1 (n) 1 1Group Candida spp. 2 (n) 1 1 2

a The number of patients with Candida spp. or IC C 0.5 or ICC C 0.4 is based on the number of patients taken at admissionb Candidemia acquired 48 h after ICU admission and within 3 weeks following ICU discharge

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Taking into account period in the model did not sig-nificantly change these results.

Results of time-series analysis for Candida spp.colonization, C.glabrata colonization during ICU stay,acquisition for C. glabrata colonization weighted by thenumber of hospitalized patients, are given in Fig. 3a–cand Table 4. Stationarity was demonstrated for eachvariable, and no significant trend in the evolution of eachvariable over time was demonstrated throughout the studyperiod.

Patients outcome

No significant change in annual mortality rates was ob-served during the study period (Table 1). No trend inmortality rate could be observed in the time-series ana-lysis (Fig. 3d; Table 4). During the study period, 41 ICUpatients were treated with antifungal drugs for provencandidemia. Among these patients, 15 acquired can-didemia at least 48 h after ICU admission. Eight patientsdeveloped a candidemia within 3 weeks following ICU

Fig. 2 Changes during the study period of the Candida spp.distribution of patients. a Percentage of patients with positivefungal colonization throughout ICU stay. b Percentage of patients

with acquired fungal colonization during ICU stay. c Percentage ofpatients with fungal negativization during ICU stay

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discharge. The incidence of candidemias acquired at least48 h after ICU admission up to 3 weeks following ICUdischarge (n = 23) did not significantly change over theyears (Table 3). Sixteen (70 %) of these 23 patients hadpositive CI before the onset of candidemia. Colonizingand infecting Candida species are the same in all cases,even if five patients were colonized with more than onespecies. Among the seven patients with negative CI andcandidemia (C. parapsilosis n = 4, C. albicans n = 3),five presented with concomitant Candida-positive cultureof catheter tips and blood culture with the same species,and 4 out 7 showed a Candida colonization with IC\0.5.Candida species distribution of these fongemias is givenin Table 3. We did not observe any azole-resistant

infecting C. albicans strain during the period (all werewild-type). Fifteen percent of C. glabrata infecting strainswere resistant to fluconazole (fluconazole MIC[32 lg/mL), without any significant change over the years.

Discussion

This study evaluated the distribution evolution of Can-dida spp. involved in the deep colonization sites of ICUpatients exposed to preemptive fluconazole therapy overthe 8-year period. A significant increase of acquired C.glabrata colonization was observed, whereas clearing of

Table 4 Evolution in subsequent months of Candida colonization, C. glabrata colonization during ICU stay, acquisition for C. glabratacolonization and mortality weighted by the number of hospitalized patients based on autoregression-moving average (ARMA) models

Augmented Dick-ey–Fuller

ARMA bestmodel

l Autoregression

Movingaverage

LowestBIC

Ljung box

Statistics p value Statistics ddl p value

Candida spp. colonization -9.05 0.001 ARMA (0.0) 23.55 0 0 1.54 1.27 6 0.97C. glabrata colonization -8.05 \0.0001 ARMA (0.1) 4.29 0 -0.13 1.02 7.82 6 0.25Acquired C. glabratacolonization

-8.93 \0.0001 ARMA (0.0) 0.54 0 0 0.78 10.21 6 0.12

Mortality -8.56 \0.0001 ARMA (0.0) 5.44 0 0 1.86 2.89 6 0.82

Fig. 3 Monthly values of Candida spp. colonization (a), C.glabrata colonization (b), acquired C. glabrata (c), and mortality(d) with their trendline, obtained from an ARMA model (see

‘‘Statistical analysis’’ for details). The values on the x-axis aremonths and the values on the y-axis are the number of patientsweighted by the number of hospitalized patients

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C. parapsilosis colonization during ICU stay significantlydecreased. No significant shift of colonization to otherCandida spp. was observed. The incidence of ICU-acquiredcandidemia did not change throughout the study period.

Data regarding the evolution of Candida spp. distribu-tion over time among IFI high-risk patients remainedcontroversial. In the early 1990s, Wingard et al. [30] re-ported a seven-fold increase in disseminated C. kruseiinfection in immunocompromized patients who receivedprophylaxis with fluconazole as compared to patients whodid not. Gleason et al. [25] reported a shift in the fungalepidemiology towardsmore resistant non-albicans species,including C. glabrata in 2 surgical ICUs, where about 2 %of the patients were treated with fluconazole. Fournier et al.[31] have shown recently that an increase in caspofunginuse in ICU over a 6-year period correlatedwith a significantincrease in C. parapsilosis isolates, whereas C. glabratadistribution did not change significantly. On the contrary, adecrease in C. glabrata and C. krusei proportions wereobserved in isolates collected from surveillance culturesafter the introduction of fluconazole for prophylaxis andtherapy in cancer patients [32]. Comparing two small seriesof ICU patients, Rocco et al. [26] did not report changes inthe epidemiology of Candida spp. after an increased use offluconazole. The percentage of non-albicans Candida inour study remained limited, in accordance with the Euro-pean literature-based review, which revealed neverthelesssome differences in the epidemiology ofCandida fungemiaamong European countries, with a higher prevalence of C.glabrata in northern and C. parapsilosis and southerncountries, highlighting the importance of health-care cen-ter-specific data on Candida epidemiology [33, 34]. As awhole, the wide discrepancies reported in the literature,recently reviewed by Maubon et al. [34], may be related todifferences in case-mix, mycological criteria (includingsampling site, threshold, IFI and/or colonization), asso-ciation with antibacterial therapy, and duration ofantifungal therapy exposure.

Mild changes in fungal ecology were observed despitea relatively wide use of fluconazole therapy in our ICU, inthe setting of an 8-year pre-emptive antifungal strategy[13]. This strategy is based on: (1) a systematic and re-peated mycological screening during ICU stay, and (2) anearly preemptive fluconazole therapy in cases of high-intensity C. albicans colonization. Thirteen percent of thepatients received pre-emptive fluconazole from 2005 to2012, with a decreasing trend in the last years of thestudy. This exposure to azole is higher in our ICU than the7.5 % reported by Azoulay et al. [24]. However, this ratemay vary depending of the patient case-mix, and a higherantifungal exposure in surgical ICU with high rate ofabdominal surgery patients could be expected [17]. Sev-eral preventive strategies based either on clinical riskfactor and/or others biomarkers (beta-D-glucan) havebeen described. In this regard, Candida score had prob-ably a more interesting highly negative predictive value,

validated in multicenter prospective studies [10, 22, 35].However, its lower positive predictive value would leadto overtreatment in patients with a score C3, especially inpatients admitted to ICU for abdominal problems withassociated risk factors. On the other hand, biomarkerssuch as beta-glucan could also be attractive, but the use-fulness of this test to guide preemptive or empiricalantifungal treatment remains to be determined [36].

We observed an increase in caspofungin consumptionafter 2009, after the publication of IDSA guidelines on IFIempirical treatment [6]. An impact on C. parapsilosisecology could be expected, as suggested by the study ofFournier et al. [31], but was not observed in our series.Several hypotheses may be raised to explain this dis-crepancy. First, we reported a more frequent clearing ofC. parapsilosis colonization during ICU stay, suggestingthat the increased fluconazole use may have decreased theemergence of C. parapsilosis, usually sensitive to thisagent. Second, the limited exposure to echinocandin inthe study period, and its well-defined use limited to em-pirical and curative treatments, were probably insufficientto produce a selection pressure. Third, the percentage ofimmunocompromised patients was higher in Fournier’sstudy [31]. Finally, the impact of caspofungin use on theincidence of C. parapsilosis was not determined byFournier et al. [31], as they only described an increase ofthe relative proportion of this species.

In patients with fungemia, Lortholary et al. reported ahigher incidence of some non-albicans Candida speciesin case of antifungal pre-exposure (i.e. C. glabrata and C.krusei, after fluconazole pre-exposure and C. parapsilosis,and to a lesser extent C. glabrata, after caspofungin pre-exposure) [23]. Moreover, they showed that the risk ofbeing infected by an isolate with decreased susceptibilityto one of these drugs was independently associated withrecent exposure to a given drug [23].

In our study, trend chi-square analysis showed an in-creased prevalence of C. glabrata colonization duringICU stay over the years. A discrepancy was observedbetween this test and ARMA analysis, which showed notrend in evolution over the years. This discrepancy maybe explained by a lack of power of time-series analysiswhen the number of events is B50. The evolution oc-curred concomitantly with an increase in caspofungin usethat deserves further discussion. A typing study of C.glabrata ICU isolates over a 2-year period revealed thatmore than 90 % of patients harbored their own strain fromICU admittance and throughout their ICU stay, and thatcross-transmission of C. glabrata strains between patientsis a very rare event in our ICU (Grenouillet F., unpub-lished data). Thus, the spread of a clonal strain wasexcluded. These trends in C. glabrata epidemiology wereobserved in our study on yeast colonization at the globalICU scale, whereas Lortholary et al’s study focused onthe impact of antifungal use at an individual scale,studying infecting yeast isolates from fungemia episodes

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[23]. Thus, the real impact of caspofungin use on C.glabrata epidemiology deserves further studies.

Our study carries several limitations. Although weused prospective databases, the retrospective design ofour study may have certain biases. These results, obtainedin a single center, may not be extrapolated to other in-stitutions or ICUs with different case-mixes of patientsand/or other practices in the use of antifungal agents.

Although recent European guidelines recommend theidentification of patients at high IFI risk who potentiallymay benefit from empirical antifungal therapy, usingclinical tools or biomarkers, the decision to treat has to beweighed against potential adverse effects. In this regard,the efficacy of prophylactic or preemptive strategies thatlead to a larger use of antifungal therapy to reduce theincidence of IFI remains a subject of debate. In our series,the incidence of candidemia acquired after ICU admissionremains low (approximately 3.5 episodes/10,000 days ofhospitalization) and compares favorably with the inci-dence reported by Lortholary et al. (6.31 episodes/10,000 days of hospitalization) [37]. However, the designof this noninterventional, observational study does notallow to assess the efficacy of the preemptive strategy onthe incidence of candidemia in surgical ICU patients, andno conclusion regarding the efficacy of the preemptivestrategy can be drawn.

We also could not test whether or not the susceptibilityof the Candida spp. to antifungal therapy had changedduring the study. Several studies have reported some al-teration in antifungal susceptibility after antifungaladministration, but this effect remained moderate. In thestudy by Fournier et al. [31], the increase in caspofunginuse was significantly correlated to an increase in caspo-fungin minimal inhibitory concentrations displayed by C.parapsilosis and C. glabrata, whereas significant declinesin fluconazole use was associated to increased overallsusceptibility of C. albicans to this drug. Rocco et al. [26]reported an increase over time of Candida spp. resistanceto fluconazole associated with an increase in fluconazoleuse in the ICU. On the other hand, Dimopoulos et al. [27]showed, over a 10-year period, that decreased suscepti-bility to all antifungals had only a sporadic distributionamong all ICU isolates. Finally, patient yeast cross-transmission was sometimes reported in the ICU context.Acquired resistance to Candida spp., although less fre-quent than intrinsic resistance, has resulted mainly from

the selection of mutants subjected to antifungal pressure,and this risk remains a major concern when antifungaldrugs are used [34].

Regular surveys of C. glabrata and C. krusei forpossible cross-transmission in our unit using microsatel-lite PCR-based typing methods showed that this could notbe excluded, but occurred in fewer than 2 % of ourcolonized patients (data not shown) [38, 39]. However,such events remain rare, and we think that it should notinduce a significant shift in fungal epidemiology of anICU. Administration of antifungal drugs before admissionto the ICU or the presence of specific risk factors mayalter the intensity of colonization or Candida spp. in-volved in the colonization, or both [10]. The lack of dataon this parameter precludes any analysis of this factor inour study.

In conclusion, this large retrospective single-centerstudy suggested that preemptive treatment of a surgicalICU’s patients highly colonized with Candida spp. wasassociated with a significant increase of acquired C.glabrata colonization, without a significant shift ofcolonization to other Candida spp. The incidence of ICU-acquired candidemia or mortality rates were not alteredover time. However, the potential detrimental impact offluconazole on Candida ecology in ICUs and/or onCandida susceptibility to antifungal drugs should beconsidered, and deserves further studies. Systematicassessment of the susceptibility of colonizing yeast iso-lates, before and after drug exposure, could allow themore precise defining of the effects of antifungal therapiesboth at the ICU and patient levels.

Acknowledgments We thank Dr E Farah for helpful discussionand B. Renaud for his help in data extraction from the pharmacydatabase. The study data were generated as part of routine work atour Institution. The financial cost of data analysis and manuscriptpreparation was supported by the Department of Anesthesiologyand Intensive Care Medicine, University Hospital of Besancon,F-25000 Besancon, France.

Conflicts of interest David Ferreira: none to declare, FredericGrenouillet: none to declare, Gilles Blasco: none to declare, Em-manuel Samain: paid consultancies for drug companies: Nycomed,Baxter, and Leo Pharma, Thierry Henon: none to declare, AlainDussaucy: none to declare, Laurence Millon: none to declare,Mariette Mercier: none to declare, Sebastien Pili-Floury: none todeclare.

References

1. Eggimann P, Garbino J, Pittet D (2003)Epidemiology of Candida speciesinfections in critically ill non-immunosuppressed patients. LancetInfect Dis 3:685–702

2. Bassetti M, Merelli M, Righi E et al(2013) Epidemiology, speciesdistribution, antifungal susceptibility,and outcome of candidemia across fivesites in Italy and Spain. J ClinMicrobiol 51:4167–4172. doi:10.1128/jcm.01998-13

3. Pfaller MA, Diekema DJ (2007)Epidemiology of invasive candidiasis: apersistent public health problem. ClinMicrobiol Rev 20:133–163. doi:10.1128/cmr.00029-06

1086

4. Arendrup MC, Sulim S, Holm A,Nielsen L, Nielsen SD, Knudsen JD,Drenck NE, Christensen JJ, JohansenHK (2011) Diagnostic issues, clinicalcharacteristics, and outcomes forpatients with fungemia. J ClinMicrobiol 49:3300–3308. doi:10.1128/jcm.00179-11

5. Puig-Asensio M, Peman J, Zaragoza R,Garnacho-Montero J, Martin-MazuelosE, Cuenca-Estrella M, Almirante B(2014) Impact of therapeutic strategieson the prognosis of candidemia in theICU. Crit Care Med 42:423–432. doi:10.1097/ccm.0000000000000221

6. Pappas PG, Kauffman CA, Andes Det al (2009) Clinical practice guidelinesfor the management of candidiasis:2009 update by the Infectious DiseasesSociety of America. Clin Infect Dis48:503–535. doi:10.1086/596757

7. Voss A, Hollis RJ, Pfaller MA, WenzelRP, Doebbeling BN (1994)Investigation of the sequence ofcolonization and candidemia innonneutropenic patients. J ClinMicrobiol 32:975–980

8. Leon C, Ostrosky-Zeichner L, SchusterM (2014) What’s new in the clinicaland diagnostic management of invasivecandidiasis in critically ill patients.Intensive Care Med 40:808–819. doi:10.1007/s00134-014-3281-0

9. Pittet D, Monod M, Suter PM, Frenk E,Auckenthaler R (1994) Candidacolonization and subsequent infectionsin critically ill surgical patients. AnnSurg 220:751–758

10. Eggimann P, Pittet D (2014) Candidacolonization index and subsequentinfection in critically ill surgicalpatients: 20 years later. Intensive CareMed 40:1429–1448. doi:10.1007/s00134-014-3355-z

11. Bassetti M, Marchetti M, Chakrabarti Aet al (2013) A research agenda on themanagement of intra-abdominalcandidiasis: results from a consensus ofmultinational experts. Intensive CareMed 39:2092–2106. doi:10.1007/s00134-013-3109-3

12. Cornely OA, Bassetti M, Calandra Tet al (2012) ESCMID* guideline for thediagnosis and management of Candidadiseases 2012: non-neutropenic adultpatients. Clin Microbiol Infect 18(Suppl7):19–37. doi:10.1111/1469-0691.12039

13. Piarroux R, Grenouillet F, Balvay P,Tran V, Blasco G, Millon L, Boillot A(2004) Assessment of preemptivetreatment to prevent severe candidiasisin critically ill surgical patients. CritCare Med 32:2443–2449

14. Paramythiotou E, Frantzeskaki F,Flevari A, Armaganidis A, DimopoulosG (2014) Invasive fungal infections inthe ICU: how to approach, how to treat.Molecules 19:1085–1119. doi:10.3390/molecules19011085

15. Eggimann P, Francioli P, Bille J et al(1999) Fluconazole prophylaxisprevents intra-abdominal candidiasis inhigh-risk surgical patients. Crit CareMed 27:1066–1072

16. Garbino J, Lew DP, Romand JA,Hugonnet S, Auckenthaler R, Pittet D(2002) Prevention of severe Candidainfections in nonneutropenic, high-risk,critically ill patients: a randomized,double-blind, placebo-controlled trial inpatients treated by selective digestivedecontamination. Intensive Care Med28:1708–1717. doi:10.1007/s00134-002-1540-y

17. Pelz RK, Hendrix CW, Swoboda SM,Diener-West M, Merz WG, HammondJ, Lipsett PA (2001) Double-blindplacebo-controlled trial of fluconazoleto prevent Candidal infections incritically ill surgical patients. Ann Surg233:542–548

18. Shorr AF, Chung K, Jackson WL,Waterman PE, Kollef MH (2005)Fluconazole prophylaxis in critically illsurgical patients: a meta-analysis. CritCare Med 33:1928–1935

19. Schuster MG, Edwards JE Jr, Sobel JDet al (2008) Empirical fluconazoleversus placebo for intensive care unitpatients: a randomized trial. Ann InternMed 149:83–90

20. Albert M, Williamson D, Muscedere J,Lauzier F, Rotstein C, Kanji S, Jiang X,Hall M, Heyland D (2014) Candida inthe respiratory tract secretions ofcritically ill patients and the impact ofantifungal treatment: a randomizedplacebo controlled pilot trial(CANTREAT study). Intensive CareMed 40:1313–1322. doi:10.1007/s00134-014-3352-2

21. De Pascale G, Antonelli M (2014)Candida colonization of respiratorytract: to treat or not to treat, will weever get an answer? Intensive Care Med40:1381–1384. doi:10.1007/s00134-014-3364-y

22. Ostrosky-Zeichner L, Shoham S,Vazquez J et al (2014) MSG-01: arandomized, double-blind, placebo-controlled trial of caspofunginprophylaxis followed by preemptivetherapy for invasive candidiasis in high-risk adults in the critical care setting.Clin Infect Dis 58:1219–1226. doi:10.1093/cid/ciu074

23. Lortholary O, Desnos-Ollivier M,Sitbon K, Fontanet A, Bretagne S,Dromer F (2011) Recent exposure tocaspofungin or fluconazole influencesthe epidemiology of candidemia: aprospective multicenter study involving2,441 patients. Antimicrob AgentsChemother 55:532–538. doi:10.1128/aac.01128-10

24. Azoulay E, Dupont H, Tabah A,Lortholary O, Stahl JP, Francais A,Martin C, Guidet B, Timsit JF (2012)Systemic antifungal therapy in criticallyill patients without invasive fungalinfection*. Crit Care Med 40:813–822.doi:10.1097/CCM.0b013e318236f297

25. Gleason TG, May AK, Caparelli D, FarrBM, Sawyer RG (1997) Emergingevidence of selection of fluconazole-tolerant fungi in surgical intensive careunits. Arch Surg 132:1197–1201(discussion 1202)

26. Rocco TR, Reinert SE, Simms HH(2000) Effects of fluconazoleadministration in critically ill patients:analysis of bacterial and fungalresistance. Arch Surg 135:160–165

27. Dimopoulos G, Velegraki A, FalagasME (2009) A 10-year survey ofantifungal susceptibility of candidemiaisolates from intensive care unit patientsin Greece. Antimicrob AgentsChemother 53:1242–1244. doi:10.1128/aac.01368-08

28. Playford EG, Nimmo GR, Tilse M,Sorrell TC (2010) Increasing incidenceof candidaemia: long-termepidemiological trends, Queensland,Australia, 1999–2008. J Hosp Infect76:46–51. doi:10.1016/j.jhin.2010.01.022

29. WHO collaborating centre for drugstatistics methodology (2014)Guidelines for ATC classification andDDD assignment, 2015. Oslo.http://www.whocc.no/atc_ddd_publications/guidelines/

30. Wingard JR, Merz WG, Rinaldi MG,Johnson TR, Karp JE, Saral R (1991)Increase in Candida krusei infectionamong patients with bone marrowtransplantation and neutropenia treatedprophylactically with fluconazole.N Engl J Med 325:1274–1277. doi:10.1056/nejm199110313251803

31. Fournier P, Schwebel C, Maubon Det al (2011) Antifungal use influencesCandida species distribution andsusceptibility in the intensive care unit.J Antimicrob Chemother66:2880–2886. doi:10.1093/jac/dkr394

32. Kunova A, Trupl J, Demitrovicova Aet al (1997) Eight-year surveillance ofnon-albicans Candida spp. in anoncology department prior to and afterfluconazole had been introduced intoantifungal prophylaxis. Microb DrugResist 3:283–287

1087

33. Montagna MT, Lovero G, Borghi Eet al (2014) Candidemia in intensivecare unit: a nationwide prospectiveobservational survey (GISIA-3 study)and review of the European literaturefrom 2000 through 2013. Eur Rev MedPharmacol Sci 18:661–674

34. Maubon D, Garnaud C, Calandra T,Sanglard D, Cornet M (2014)Resistance of Candida spp. toantifungal drugs in the ICU: where arewe now? Intensive Care Med40:1241–1255. doi:10.1007/s00134-014-3404-7

35. Leon C, Ruiz-Santana S, Saavedra P,Almirante B, Nolla-Salas J, Alvarez-Lerma F, Garnacho-Montero J, LeonMA (2006) A bedside scoring system(‘‘Candida score’’) for early antifungaltreatment in nonneutropenic criticallyill patients with Candida colonization.Crit Care Med 34:730–737. doi:10.1097/01.ccm.0000202208.37364.7d

36. Tissot F, Lamoth F, Hauser PM et al(2013) beta-glucan antigenemiaanticipates diagnosis of blood culture-negative intraabdominal candidiasis.Am J Respir Crit Care Med188:1100–1109. doi:10.1164/rccm.201211-2069OC

37. Lortholary O, Renaudat C, Sitbon K,Madec Y, Denoeud-Ndam L, Wolff M,Fontanet A, Bretagne S, Dromer F(2014) Worrisome trends in incidenceand mortality of candidemia inintensive care units (Paris area,2002–2010). Intensive Care Med40:1303–1312. doi:10.1007/s00134-014-3408-3

38. Shemer R, Weissman Z, Hashman N,Kornitzer D (2001) A highlypolymorphic degenerate microsatellitefor molecular strain typing of Candidakrusei. Microbiology 147:2021–2028

39. Grenouillet F, Millon L, Bart JM,Roussel S, Biot I, Didier E, Ong AS,Piarroux R (2007) Multiple-locusvariable-number tandem-repeat analysisfor rapid typing of Candida glabrata.J Clin Microbiol 45:3781–3784. doi:10.1128/jcm.01603-07

1088