Public Health since the beginning: Neonatal incubators safety in a clinical setting

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ContentslistsavailableatScienceDirect

Journal

of

Infection

and

Public

Health

jo u r n al ho me p ag e :h t t p : / /w w w . e l s e v i e r . c o m / l o c a t e / j i p h

Public

Health

since

the

beginning:

Neonatal

incubators

safety

in

a

clinical

setting

Mattia

Fattorini

a

_,

_Giuseppe

_Buonocore

b

_,

_Daniele

_Lenzi

c

_,

_Sandra

_Burgassi

b

_,

Rosa

M.R.

Cardaci

b

_,

_Klaus

_P.

_Biermann

d

_,

_Gabriele

_Cevenini

e

_,

_Gabriele

_Messina

b,∗

a_Post_Graduate_School_of_Public_Health,_University_of_Siena,_Italy

b_Department_of_Molecular_and_{Developmental}_Medicine,_University_of_Siena,_Italy c_Medical_Management,_“Le_Scotte”_Teaching_Hospital,_Siena,_Italy

d_Clinical_Trial_Ofﬁce,_“Meyer”_Teaching_Hospital,_Florence,_Italy e_Department_of_Medical_{Biotechnologies,}_University_of_Siena,_Italy

a

r

t

i

c

l

e

i

n

f

o

Articlehistory:

Received17November2017 Accepted6March2018 Keywords:

HealthcareAssociatedInfections Disinfection

Neonatalincubators Italy

a

b

s

t

r

a

c

t

Background:Theroleofenvironmentalcleaningasaneffectivemeasuretocontainthediffusionof Health-careAssociatedInfections(HAIs) hasalreadybeendemonstrated.Amongmedicaldevices,neonatal incubatorshavebeenrecognizedasasourceofpathogensinvolvedinthespreadofHAIs.Aimofthe studywastoassesstheefﬁcacyofadisinfectionprotocolforneonatalincubators.

Methods:Thecrosssectionalstudytookplaceinthe“NeonatalPediatricUnit”oftheTeachingHospital ofSiena:twentyincubators,usedforcriticalnewborns,wereswabbedin13samplingpointsbeforeand aftertheimplementationofthedisinfectionprotocol.Sanitationprocedureswereperformedbytrained staff,implementingtheproductUmonium38® _Neutralis_as_{disinfectant.}_Different_culture_media_for_the

identiﬁcationofthemicrobialcontaminationwereadopted:plateswereincubatedforthepropertime andtheresultswerereferredtoColonyFormingUnits(CFUs)/swabperpoint.Descriptivestatistical analysiswasperformed.Itwasalsoevaluatedthe95%conﬁdenceinterval(C.I.)ofthemeanandthe percentageofCFUsreductionbythebootstrapbiascorrectedandacceleratedresamplingmethod. Results:Matchedpointsanalyzedwere313.TheaverageCFUspercentageofreductionwas93.5%[C.I. 90.6–95.9%]:itwashigher,97.0%[C.I.94.1–99.1%],inpointsplacedinsidetheincubatorsstructure comparedtothe88.4%[C.I.83.6–93.0%]obtainedoutside.

Conclusion:Thedisinfectionprotocolachievedgoodresults.Routinesurveillanceandsupervisionofthe variousaspectsofthedisinfectionprocesses(procedures,staffanddisinfectants)couldguaranteeasafe environmentduringtheﬁrstdaysofbabies’life,avoidingharmfulconditionsforthenewborns’health.

©2018TheAuthors.PublishedbyElsevierLimitedonbehalfofKingSaudBinAbdulazizUniversity forHealthSciences.ThisisanopenaccessarticleundertheCCBY-NC-NDlicense(http:// creativecommons.org/licenses/by-nc-nd/4.0/).

Introduction

Severalstudiesdemonstratedtheroleofenvironmental

clean-ingasaneffectivemeasuretocontainthespread ofHealthcare

Associated Infections (HAIs) [1–4]: in fact, it has been widely

reportedthatvariouspathogens(e.g.Methicillin-resistant

Staphy-lococcusaureus,Clostridiumdifﬁcile,SerratiaMarcescens,Norovirus,

etc.)could survive for long periods onenvironmental surfaces

and medical equipment [5,6]. These pathogens can be directly

∗ Corresponding author at: Department of Molecular and Developmental Medicine,PostGraduateSchoolofPublicHealth,UniversityofSiena,Italy.

E-mailaddress:[email protected](G.Messina).

transferredtothepatients’skinbydirectcontactofcontaminated

surfaces/equipmentorindirectlyviathehandsofhealthcare

work-ers[7].Amongmedicalequipment,neonatalincubatorshavebeen

recognisedasasourceofmicroorganismspotentiallyimplicated

inthediffusionofHAIs[8–13].Duetotheirimmatureimmune

system,newbornsareverysusceptiblefortheacquisitionofHAIs;

moreover,babieswithparticularriskfactors(e.g.verylowbirth

weight,prematurity,maternalintakeofcorticosteroids,

mechan-icalventilation,etc.)showanhigher risktodevelop potentially

life-threateningconditionssuchasthesocalledLateOnsetSepsis

(LOS),whichcanoccurafterthethirddayoflife[14,15].Hence,an

adequatedisinfectionprotocolshouldbeimplementedinorderto

guaranteeasafeenvironmentforthebabiesintoneonatal

incuba-tors.

https://doi.org/10.1016/j.jiph.2018.03.001

1876-0341/©2018TheAuthors.PublishedbyElsevierLimitedonbehalfofKingSaudBinAbdulazizUniversityforHealthSciences.Thisisanopenaccessarticleunderthe CCBY-NC-NDlicense(http://creativecommons.org/licenses/by-nc-nd/4.0/).

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Aimofthestudywastoassesstheeffectivenessofaprotocolfor

thedisinfectionofneonatalincubatorsinaclinicalsettingtowards

differentmicroorganismspotentiallyimplicatedinthediffusionof

HAIs.

Materialandmethods

Studypopulation

A cross-sectional study design with comparisons of Colony

FormingUnits(CFUs)beforeandaftertheimplementationofan

incubatorsdisinfectionprotocolwascarriedout.Thestudytook

placebetweenSeptember2016andMarch2017inthe“Neonatal

PediatricUnit”ofthe750-bedTeachingHospitalofSiena,Italy.

Performingliteratureinvestigationsitwasassessedwhichwere

themostlikelypointstoinvestigate,consideringthelikelihoodand

amountofcontamination.Threedifferentmodelsofincubators,for

atotalof20,weretestedintheNeonatalward:twelveATOM©

Incu-I(AtomMedicaUSA,Wexford,PA),sixATOM© _V2100-G_(Atom

MedicaUSA,Wexford,PA)and twoGiraffe© _Incubator_(General

ElectricCompany,USA).

Foreachincubator,thefollowing13matched(pre/post

disinfec-tion)samplingpointsweretested:porthole(1)andportholelock

(2)placedoutsidethecanopyatbaby’sheadaccesspoint;porthole

(3),smallwallatbaby’sfeetside(4)andatheadside(5)inthe

inte-riorofthecanopy;thesuperiorfaceofthemattressonthehead

(6)andbuttock/feet(7)level;thesurfaceoftheplatformin

con-tactwithinferiorfaceofthemattress,atvicinityofhead(8),theair

conditioningandthehumiditychambers(9–10),thecontrolpanel

(11),theprobe/sensorforskintemperature(12)andtheaccessport

cover(13).Samplingpointsnumber1–2–11–13wereclassiﬁedas

“outside”theincubator’sstructure, whiletheotherpointswere

classiﬁedas“inside”(seeFig.1).

Disinfectionprotocol

The protocol for the sanitation procedures adopted in the

NeonatalUnitwasorganisedinﬁvedifferentphases:(i)

switch-ingoffoftheincubator,ensuringitscoolingandtheremovalofthe

powercord;(ii)disassemblingoftheremovableparts;(iii)

disin-fectionoftheremovableparts;(iv)disinfectionofﬁxedparts;(v)

reassemblingofallthecomponents.

Incubators in the ward were routinely disinfected

follow-ing a protocol adopted by the Unit, which included the use

ofthedisinfectantUMONIUM38® _Neutralis

(N-benzy-N-dodecyl-N,N-dimethyl-ammonium chloride/

N-benzyl-N,N-dimethyl-N-tetradecyl-ammoniumchloride),atamanufacturerrecommended

concentrationand contacttimeof2.5%and10minrespectively.

DisinfectionprocedureswereperformedbytrainedstaffoftheUnit

whenthenewbornwasdischarged/transferredorthelengthofstay

ofthenewborninthesameincubatorlastedmorethansevendays.

Itwasnotpossibletotracetheoperatorsthatprovidedthe

dis-infectionproceduresbecausethecomplexityoftheworkshift,the

impossibilitytoscheduletheirtimeof protocolimplementation

andtheirturnoverinseveralwardsoftheHospital.

Samplingprocedures

Sampling procedures of each incubator were performed by

trained staffof theDepartment of Molecularand

Developmen-talMedicineoftheUniversityofSiena.Afterthedisplacementof

thebabyhostedintheincubator,within30min,swabs(LP

Ital-iana)werecarriedoutbeforeandafterthedisinfection(upto13

matchedsamplingpoints,dependingfromthepresence/absenceof

thepointintheswabbedincubator).Samplingfromthe20

incu-Fig.1. Incubators’samplingpointstestedinthestudy.Inblack,pointsclassiﬁedas “outside”theincubator’sstructure.Ingrey,pointsclassiﬁedas“inside”.1—Porthole (external,head);2—Portholelock(head);3—Porthole(internal,feet);4—Smallwall (feet);5—Smallwall(head);6—Superiorfaceofthemattress(head);7—Superiorface ofthemattress(buttock/feet);8—Platformincontactwithinferiorfaceofthe mat-tress(head);9—Airconditioningchamber;10—Hhumiditychambers;11—Control panel;12—Probe/sensorforskintemperature;13—Accessportcover.

batorsinvolvedinthestudywereperformedbetweenthe28thof

September2016andthe13thofFebruary2017.

Apotentialtotalamountof26swabsperincubatorwas

col-lected. In case of lack of a sampling point, collection was not

performed.Eachofthe13pointswasentirelyswabbedinboththe

phasesofsampling.

Incubatormodelanddateofcollectionwerealsorecorded

dur-ingtheswabbingphase.

Laboratorymethods

Aftertheperformingoftheswabs,samplesweretransferred,

within30min,tothelaboratoriesoftheDepartmentofMolecular

andDevelopmentalMedicinefortheproperanalysis.Inthe

labora-torieseachswab,immersedin2mlofPhosphateBufferedSaline

(Sigma-Aldrich® PBS),wasmixed withvortex and 200␮l were

sowninduplicate,beforeandafterthetreatmentprotocol,inthe

followingthreemedia:i)BDPlateCountAgar(PCA),for

determina-tionofaerobicmesophiliccontamination;ii)BDSabouraudGlucose

Agar,foridentiﬁcationofmouldsandyeasts;iii)BDCHROMagarTM

OrientationMedium,forquantitativeandqualitativeidentiﬁcation

ofdifferentbacteria.

Oncesowed,alltheplateswereincubated.ColonyFormingUnits

(CFUs)onPetridisheswithPCAandCHROMagarOrientationhad

a countafter24 and48hof incubationat36◦C,whileCFUs on

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Foreachsamplingpoint,themeanofCFUsobtainedfromthe

sowninduplicateof200␮lonthedifferentmediawascalculated;

then,themeanwasreferredtoCFUs/swabperpoint.

Statisticalanalysis

Incubator ID and model, type of growth medium, sampling

point,positionofsamplingpointas“inside”or“outside”the

incuba-torstructure,CFUsbefore/aftertreatmentinthespeciﬁcsampling

pointandreductionofCFUsbeforeandaftertreatmentinthe

sam-plingpointwerethevariablesinsertedintothedatabase.

Aftercheckingthedataforincongruities,pointswereexcluded

fromtheanalysis,when:(i)noCFUswerefoundbothbeforeand

afterdisinfectionand(ii)aCFUsdifference>10wasobservedafter

thedisinfection,inrespectwiththenumberofCFUsbefore

treat-ment.Thisoperationwascarriedoutinordertoeliminatepossible

outlierscaused by any accidental procedurenot related tothe

mechanismofactionofthedisinfectingprocedure,whichwasof

coursehypothesizednottocauseanincreaseinmicrobialcharge.

Indeed,toaccountalsoforlittlerandomﬂuctuationaroundzero,

evenslightlydifferencesexceeding10CFUswereconsideredfor

pointexclusion.

Overall,pre/postdisinfectioncomparisonsweremadeandalso

stratiﬁedanalysis on: incubator model, microbiologicalgrowth

mediumandposition(inside/outside)wereperformed;forallthe

comparisonsitwasestimatedthemeanofCFUsreduction,the

max-imumabsolutereductioninasinglesamplingpointandaverage

CFUsreductionpercentage.

Moreover,bothformeanandpercentageofCFUsreduction,it

wasevaluatedalsothe95%conﬁdenceinterval (95%C.I.)bythe

bootstrapresamplingmethod,biascorrectedandaccelerated.

IBMSPSS®software,version10,wasusedforallstatistical

anal-ysis,exceptforthebootstrapevaluationof95%C.I.performedwith

MATLAB®software.

Results

Fig.2showsthenumberofpotentiallyavailablepoints(N=780)

andtheﬁnalmatchedpoints(N=313)enrolledintheanalysis.

Ofthese313points,therewasrespectivelyameanofCFUsand

percentagereductionof209(95%C.I.141–289)and93.5%(95%C.I.

90.6–95.8%).Themaximumreductionachievedwas5730CFUs.

Beforethedisinfection,onthe756swabbedsamplingpoints

BDSabouraudGlucoseAgaridentiﬁed56(7.4%)samplingpoints

colonised by yeasts and 21 (2.8%) by moulds. Furthermore,

group“KES”(Klebsiella-Enterobacter-Serratia)wasidentiﬁedbyBD

CHROMagarTM_Orientation_Medium_in₂₄_(3.2%)_sampling_points,

followedby Enterococcus spp. in18 points (2.4%).“PMP” group

(Proteus-Morganella-Providencia)wasidentiﬁedﬁvepoints(0.67%),

Pseudomonasspp.infourpoints(0.52%)andStaphylococcus

sapro-phyticus in two points (0.26%). Moreover, Escherichia coli and

Streptococcusagalactiaeweredetectedinonesinglepoint(0.13%

both),whileCFUsidentiﬁableas“Otherbacteria”werefoundin95

points(12.6%).

Detailed results regarding reductions stratiﬁed by model,

growthmediumandsamplingpointpositionareshowedinTable1.

Discussion

It has been demonstrated how an adequate environmental

cleaningisaneffectivemeasuretoavoidthediffusionof

microor-ganismspotentiallyinvolvedinHealthcareAssociatedInfections

(HAIs).Anefﬁcaciousprocessofsanitationofneonatalincubators

ishighlyrecommended:neonatalincubatorshavebeenidentiﬁed

assourceofthesemicroorganisms,whichcouldbealsotransferred

Fig.2.Flowchartrepresentingthereductionofsamplingpointsadoptedinthe analysis.

tothenewbornsbythehandsofhealthcareworkerstouchingthem.

Furthermore,theimmunesystemofthenewbornsisimmature,so

theirsusceptibilitytoHAIsisrelevant.

Theimplementationof theprotocol showeda CFUs average

reductionofatleast91.2%(95%C.I.85.5–96.1%,inIncubatorATOM©

V2100-G).Itshowedbetterresultsagainstmicrobial

contamina-tionsidentiﬁableusingBDSabouraudGlucoseAgarmedium(96.8%,

95%C.I.93.8–99.2%).Furthermore,pointsbelongingtotheGiraffe

incubatorshowedanhigherCFUsaveragereduction(95.1%,95%

C.I.84.4–100%).

Interestingly,CFUsaveragereductionwashigher(p<0.05)in

pointsplacedinside(97%,95%C.I.94.1–99.1%)theincubator

struc-turecompared tothoseoutside (88.4%,95%C.I. 83.6–93%):this

aspectcouldberelatedtoanmajorattentioninsanitation

proce-duresprovidedbythededicatedstafftowardspointslocatedclose

tothebaby.

Inthestudy36/756(4.8%)discrepancies(i.e.aCFUsdifference

>10observedafterthedisinfection,inrespectwiththenumberof

CFUsbeforetreatment)werefound.Theseeventswereprobably

duetolackofcomplianceindisinfectionprocedures:infact,the

entireprocessofsanitationcanbecompromisedbyseveral

fac-tors,suchas:(i)lowadherencetoprocedures,(ii)lackoffeedback

inroutinecontrols, (iii)wronghumanbehaviours or(iv)

inade-quateimplementationofthecleaningprocedures.Duringallthe

studythe laboratories, where themicrobial analysiswere

con-ductedandthe“NeonatalPediatricUnit”remainedincontactto

monitortheactivitiesandtoprovidefeedbackwhichcouldbe

use-fulfor:(i)guaranteeinghighhygienicstandardforthebabies,(ii)

standardizingandimprovingthedisinfectionprocedureand,asfar

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Table1

CFUsreductionmean,maximumCFUsreductionandCFUsaveragereductionstratiﬁedforincubatormodel,growthmediumandpositionofthesamplingpoint.

Points(n.) CFUsreductionmean[95%C.I.] Max.CFUsreduction CFUsaveragereduction(%)[95%C.I.]

Notstratiﬁed 313 209[141–289] 5730 93.5%[90.6–95.8] Model ATOM©_V2100-G ₈₅ ₁₀₃_[53–167] ₁₈₃₀ _91.2%_{[85.5–96.1]} ATOM©_Incu-I ₂₀₀ ₂₅₁_[146–384] ₅₇₃₀ _94.2%_{[91.0–96.9]} Giraffe©_Incubator ₂₈ ₂₂₉_[82–404] ₁₇₇₀ _95.1%_[84.4–100] Medium PCA 118 205[99–330] 5730 91.6%[86.6–95.7] Sabouraud 76 170[80–274] 2880 96.8%[93.8–99.2] Orientation 119 238[112–394] 5550 93.3%[88.3–97.0] Position Inside 184 256[152–377] 5730 97.0%[94.1–99.1] Outside 129 143[79–217] 3530 88.4%[83.6–93.0]

anauditholdonthe28thofSeptember2016,consequentlytothe appearanceofsomediscrepanciesinthepre/postsanitationphase, wealerted theoperatorsofthe“NeonatalPediatricUnit”. After theaudit,divergencesinthepre/postanalysisdecreased/ceased. Thisaspecthighlightstheimportanceof routinesurveillanceof disinfectionprotocols, inordertoensureasafeenvironmentto newborns.Improvementssuggestedafterthe28thofSeptember weremainlyrelated to:(i)using ofthedisinfectantatthe rec-ommendedconcentration,(ii)allowingdisinfectanttoactforthe propercontacttimeonthedifferentsamplingpoints,(iii)paying attentiontochangecleaningclothaftereveryincubatorscleaning oriftheclothappearedvisiblydirt.

Themostcriticalparttodisinfectemergedtobethe“humidity chamber”,whichcontainswaterusedtoadjustthehumiditylevel insidethecanopy.Althoughthelevelofcontaminationlowered afterthedisinfectionprocedures,itremainedsubstantial.In par-ticular,intwosampledincubators(oneATOM©_V2100-G_and_one

incuba-tor,andforBDPlateCountAgarandBDCHROMagarTM_Orientation

incuba-torswerebothsampledbeforeauditholdthe28thofSeptember 2016andtheconsequentadvicetotheoperatorsofthe“Neonatal PediatricUnit”.Thesediscrepanciescanbereasonablyattributable to:(i)alackofproperimplementationofthedisinfection proto-cole.g.ﬁllingthehumiditychamberwithcontaminatedwateror, morelikely,usingacontaminatedclothfordryingthesurfacesof thechamber,(ii)alowand/orsporadiccontaminationofawet sur-facemaydeterminateacompleteandmassivecontaminationof allthenearestzones.Becauseoftheimportanceofthissampling point,particularattentionshouldbetakentomaintaingoodlevel ofdisinfection.

Inadditiontotheimportancetouseanappropriate disinfec-tanttoobtainanadequatesanitation,alsothecleaningstaffhasa remarkableimportance:itsproperformationshouldbeconsidered fundamentalinordertoobtainhighqualitystandards.Boyceetal.

[16]demonstratedhow,withnocleaningstaffeducation,huge

dif-ferencescanbefoundamongthestaffmembersincertainaspectsof

cleaningprocess,e.g.materialsusedandtimededicatedin

disin-fectionofvarioussurfaces.Inordertoavoidthesediscrepancies,

staffshouldbeperiodicallytrained and educated:inparticular,

notionsshouldbeprovidedtowardsargumentssuchashand

wash-ing,implementingchecklists,identifyingsurfacesmoreatrisktobe

colonizedbypathogens,correctuseofdisinfectants.

Aboutthesafetyoftheprotocol,nosecondaryeffects(e.g.breath

discomfort,redpatches,itch)wereobservedonnewbornshostedin

incubatorsaftertheimplementationofthedisinfectionprocedures,

neithervisualdetectablechangesonthesanitizedsurfaceswere

detected.

LateOnsetSepsis(LOS)isalifethreateningconditioncaused

byGrampositivebacteriainabout70%ofcases,whileGram

neg-ative ones are involved in 18% of LOS[17]. While Early Onset

Sepsis(EOS)isrelatedtoaverticaltransmissionfrommother

(bac-teria colonizing maternal perineum,chorioamnionitis,maternal

haematogenoustransmission),LOScanbedevelopedafteran

hor-izontaltransmissionfromnosocomialenvironments[18].Because

ofamortalityof36%inverylowbirthweightbabiesagedbetween

8–14days [17],measures topreventcolonizationby pathogens

ofenvironmentalsurfacesandmedicalequipmentisimportant.

Inourstudy,severalmicroorganismsinvolvedintheacquisition

ofHAIs(e.g.KESgroup)werepotentiallyidentiﬁedonthe

incu-batorsenrolledinthestudyusingBDCHROMagarTM_Orientation

Medium.AmongKESgroup,Serratiamarcescenswasalready

recog-nisedasanharmfulpathogenforthehealthofthenewbornsandit

waslinkedtothepossibilityofacquisitionofLOS[5,17]:this

bac-terium,implicatedinmanyoutbreaksinNeonatalIntensiveCare

Units,canbeidentiﬁedondifferentenvironmentalsurfacesaround

thenewborns.S. marcescensinfectionsin babiesarepotentially

life-threatening:hencetheimportanceofaneffectivedisinfection

protocolacquiresvitalrelevance.

Thisstudyhasseverallimits:ﬁrst,onlytwentyincubatorswere

sampledduringthestudyperiod:however,datafromthe313

sam-pling pointsavailable forthe statisticalanalysiswere managed

withthebootstrapresamplingmethod,allowingtoobtainreliable

resultsalthoughthenumberofsamplingpointsusable;second,it

wasnotpossibletorecognizeeachtimethevariousstaffmembers

whoperformedthedisinfectionoperations:thiscouldhavebeen

allowtoorganizeanad-hoctrainingforthosestaffmemberswho

didnotperformedthesanitationproceduresaccordingthe

pro-tocol;third,wewerenotabletodeterminethetimebetweenan

incubatordisinfectionprocessandthepreviousone:infact,after

eachdisinfectionprocessandbeforetheplacementofanewborn

intothesameincubator,itcouldhavebeenremainednotusedand

storedintotheUnitforanunknownamountoftime.

Conclusions

Theimplementationofthedisinfectionprotocolachievedgood

resultsespeciallyaftertheAuditwhichremindedhowtoperform

thecorrect actionduring thesanitationprocedures. Inorder to

avoiddangerstothebaby’shealth(seetheacquisitionoflife

threat-eningconditionssuchasLOS),boththeuseofproperdisinfectant,

therespectofvalidatedproceduresandanadequatetrainingof

thecleaningstaffneedtobeconsideredaspartofthefull

pack-ageofeverysanitationaction.Inaddition,routinecontrolsshould

beperformedandincludedina surveillancesystemin orderto

maintaingoodhygienestandardandtoassureasafeenvironment

forthenewborns.Thepossibilitythatcertainpathogens(including

thedrug-resistantones)cansurviveforlongperiodoninanimate

surfacesshouldincreasethealertness.Thedrawingupand

imple-mentationoftheseaspects shouldbepartof everydisinfection

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Acknowledgements

WeexpressgratitudetotheHospitalDirectionofthe

Teach-ingHospitalofSienafortheauthorizationinconductingthestudy,

tothe nursesElina Lolli and ValentinaCioncoliniand thestaff

“NeonatalPediatricUnit”forthesupportinschedulingthe

incu-batorssamplingsandthestaffoftheDepartmentofMolecularand

DevelopmentMedicineforthelaboratoriesactivities.

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