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1RiskofBabesiaInfectionbyBloodTransfusionandPotentialStrategiesforDonorTesting:IntroductionSanjaiKumar,PhDDivisionofEmergingandTransfusion-TransmittedDiseasesOfficeofBloodResearchandReviewCBER,FDABloodProductsAdvisoryCommitteeMeetingJuly26,20102IssueforBPAC•Basedonariskanalysis,dotheavailabledatasupportdevelopmentofaregionallyselectivedonortestingstrategytoreducetheriskoftransfusion-transmittedbabesiosis.•Pleasecommentonthesuitabilityofdonorscreeningeitherbyanucleicacid-basedtest,anantibodytest,orboth,giventhecurrenttechnologylimitations.3Background–I•Babesiosis,atick-bornezoonosis,iscausedbyinfectionwithintraerythrocyticprotozoansofgenusBabesiathatbelongtophylumApicomplexea.•ThemostprevalentspeciesinU.S.isBabesiamicroti.TheotherreportedspeciesareB.duncani(formerlycalledWA1-typeBabesia)andrelatedorganisms(CA1-typeBabesia)and“B.divergens-like”agentssuchasMO1.4LifeCycleofBabesiamicrotiWhite-taileddeer(Hosttoticks)White-footedmouse(Reservoirhost)5Background–II•EndemictransmissionisreportedmostlyinNortheastern,Mid-AtlanticandUpperMidwesternstatesincludingConnecticut,RhodeIsland,NewYork,Massachusetts,NewYork,NewJersey,NewYork,WisconsinandMinnesota•Severalotherstateswithoutrecognizedprevalenceareasalsoreportedbabesiosiscasesduetoinfectionsacquiredduringtraveltoendemicareas6•Clinicalillnessrangesfromasymptomatictomildtolife-threateningseveredisease.Neonates,immuno-compromisedandasplenicpersonsandelderlyareatthehighestriskofseveredisease.•Highestnumberofclinicalcasesandtransfusion-transmittedcasesofbabesiosisarereportedintheU.S.•Currently,babesiosisisnotareportablediseaseinallstates,andisnotanationallynotifiabledisease.Background–III7Geographicaldistributionofbabesiosisbeneficiaryclaimsindifferentstatesin2008(n=1543;CMSdataset)428211207128908080504037211615131212100100–5049–2524–124States4States2States6States8Transfusion-TransmittedBabesiosis(TTB)intheU.S.-I•TTBfirstreportedin1979•Sincethen,morethan100casesand11deathsreported–ThemajorityTTBcasescausedbyB.microti–Afewnon-B.microticasesofTTB9Transfusion-TransmittedBabesiosis(TTB)intheU.S.-II•TTBaparticularconcerninneonates-In2007,threeinfectionsinneonatesataRhodeIslandhospitalfromasingledonor-In2009,threeinfectionsataVirginiahospitalfromasingledonor•Whileunder-reported,B.microtiisoneofthemostfrequentlyreportedtransfusion-transmittedinfectiousagents.10FDAFatalityReportsSuggestIncreasedRiskofTTBSince2005FiscalYearNo.ofReportsFY981FY99-FY050FY06-FY089FY10111BabesiaTransmissionisRegionalwhileTTBRiskisSystemic•MostTTBisacquiredinthesameregionwherebloodiscollectedandused,however–TTBhasoccurredinnon-prevalenceareasfromdonorswhohadtraveledtoarecognizedendemicarea•Among9fatalities,4implicateddonorsand5recipientsdidnotliveinanendemicarea•17ab-positiveimplicateddonors,11werefromendemicareaswhile4werefromnon-endemicareas–Donorswhonormallyresideinendemicareasmaydonateelsewhere–BloodproductsareoftenshippedbetweenwidelyseparatedregionsacrosstheU.S.12Transfusion-transmittedbabesiosiscasesintheU.S.between2004-2008(n=63;CDCdatabasedonstateofdonation)11111111124461513442States1State14States1010–55Fortwocasesstateofdonationisunknown13ClinicalPresentationofTTB•TTBcanbeasymptomaticorpresentasaflu-likeorfulminantfebrileillness,usuallywithin1to9weekspost-transfusion(thoughdelaysof3monthscanoccur)•Fatalityratesvaryfrom3%-20%•Signsandsymptomsresemblenaturalinfection–Flu-likeillnessaccompaniedbyhemolysisischaracteristic–Alteredmentalstatus,renalfailure,pulmonarycompromise,AdultRespiratoryDistressSyndrome,andDisseminatedIntravascularCoagulopathyareseeninseverecases14VariableGeographicRiskofTTB•Earlierreportssuggestedthatapproximately16%oftheUSpopulationliveinareaswheretick-borneBabesiatransmissionsoccur(mainlyNJ,NY,CT,RI,MA,WI,MN)•Inendemicareas,riskofBabesiainfectionvariesgreatlyandishighlylocalized15AreasofBabesiaTransmissionareExpanding•Emergenceoftick-borneBabesiainfections-Increasedrecognitionanddiagnosisofbabesiosis-Increasinglycloserhumanhabitattoticks-Significantlyincreaseddeer/tickpopulations16Tick-borneTransmissionisSeasonal,whileTTBRiskisAllYear•Thetick-borneBabesiatransmissionseasonisgenerallyfromMaythroughSeptember,however–8/9fatalTTBcasesweretransfusedbetweenAugustandDecember.–ATTBcaseinAprilwaspresumedduetoadonationfromanasymptomaticchronicallyinfectedperson–Seropositiveand/orparasitemicdonorshavebeenfoundallyearround17BloodComponentsthatareImplicatedtoCauseTTB•TTBhasbeencausedbyRBCsandplatelets–B.microtiinbankedRBCsurviveat4oCforatleast35days–CryopreservedRBCscancauseTTB–Leukocytereductionandirradiationdonotclearparasites18CurrentStrategiestoPreventTTBareInsufficient•Usingastandardized,FDA-recognizeddonorhistoryquestionnaire,donorsareaskediftheyhaveeverhadbabesiosis–Donorswithaclinicalhistoryofbabesiosisaredeferredindefinitely,however–Mostbabesiosisisasymptomaticandcanpersistformonthstoyears,renderingquestioninglargelyineffective•Tickbitehistoryisbothpoorlysensitiveandnon-specific•DonordeferralforresidenceinortraveltoanendemicregionoftheUSisimpracticalduetoimpactonsupply•NoFD