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ACELLULARAUTOMATONMODELFORTHETRANSMISSIONDYNAMICSOFSCHISTOSOMIASISYUNLIU,KAICHU,XIAOLIXU,HAIWEIWUDEPARTMENTOFPATHOGENBIOLOGYNANJINGMEDICALUNIVERSITYNANJING,CHINACHENGWANDEPARTMENTOFPUBLICSERVICEMANAGEMENTNANJINGMEDICALUNIVERSITYNANJING,CHINAABSTRACTINTHISPAPER,ANEWSTOCHASTICMODELBASEDONCELLULARAUTOMATAISESTABLISHEDTOSIMULATETHEOCCURRENCEANDDEVELOPMENTOFSCHISTOSOMAJAPONICUMSJAPONICUMINFECTIONINANENDEMICPOPULATIONWEINCLUDEDTHEPROCESSOFTHEPATHOGENINVASIONFROMEXPOSURETOWORMDEVELOPMENTANDTILLWORMDEATHWHENTHEINFECTIONISCLEAREDINTHEMODELWEFURTHERUTILIZEDTHEMODELTOPREDICTTHEPREVALENCEASTHEOUTCOMESOFTHESELECTEDCHEMOTHERAPYCARRIEDOUTINJIAHUVILLAGECOMPARINGMODELPREDICTEDPREVALENCEANDINTENSITIESWITHTHEOBSERVEDPARAMETERS,ITISANTICIPATEDTHATOURCELLULARAUTOMATONTRANSMISSIONMODELCANSERVEASATOOLFORSTUDYINGSCHISTOSOMIASISTRANSMISSIONDYNAMICSINENDEMICAREASKEYWORDSSJAPONICUM；CELLULARAUTOMATA；SJCAMODEL；TRANSMISSIONDYNAMICS；PREVALENCE；INTENSITYOFINFECTIONIINTRODUCTIONSCHISTOSOMIASISISAMAJORPARASITICDISEASETHATRANKSSECONDONLYTOMALARIAINTERMSOFHUMANSUFFERINGINTHETROPICSAMONGTHETHREESPECIESOFSCHISTOSOMES,ONLYSJAPONICUMISENDEMICINCHINAANDMAINLYDISTRIBUTEDINTHEAREASOFINTERMEDIATEANDLOWERREACHESOFTHEYANGTZERIVER,ESPECIALLYTHEPOYANGLAKEANDDONGTINGLAKE1,2THESIMULATIONOFDISEASEDYNAMICSISVITALLYIMPORTANTASITENABLESONETOBETTERUNDERSTANDTHEEPIDEMIOLOGYANDCONTROLMEASURESOFSCHISTOSOMIASISINTHEPASTFEWDECADES,MANYRESEARCHERS35DEVOTEDTOTHEMATHEMATICALMODELFORTHETRANSMISSIONDYNAMICSOFSCHISTOSOMIASISBYEQUATIONBASEDMODELINGEBM,THEMAINFORMOFWHICHWEREASERIESOFDETERMINEDDIFFERENTIALEQUATIONSAFTERMATHEMATICALMODELSWEREESTABLISHED,THESHORTTERMANDLONGTERMOUTCOMESOFDISEASESCANBEPREDICTEDINAPARTICULARPARAMETERSSETTINGITISNOTEDTHATTHOSEMODELSWEREPERFORMEDINCONTINUOUSSYSTEMSIMULATIONTRANSLATIONOFTHEPOPULATIONDYNAMICSANDSTOCHASTICSINTODIFFERENTIAL/DIFFERENCEEQUATIONFORMWASNOTTRIVIALBESIDES,THOSEMODELSUSUALLYTRACKEDTHEAVERAGEWORMBURDENWITHOUTTAKINGTHEVARIATIONSAMONGINDIVIDUALSINTOACCOUNTITISIMPORTANTTONOTETHATOMITTINGTHESTOCHASTICITYORTHEDISCRETENATUREOFTHEINDIVIDUALSOFTENLEADSTOABSURDRESULTSMOSTRECENTLY,COMPUTERSTOCHASTICSIMULATINGMETHODSHAVEBEENWIDELYUSEDTOMIMICTHETRANSMISSIONANDIMMUNEDYNAMICSOFDISEASES6,7,INCLUDINGCELLULARAUTOMATACACAISADYNAMICALSYSTEMINWHICHSPACE,TIME,ANDTHESTATESAREDISCRETEUNLIKEEQUATIONBASEDMODELS,CAMODELSFOCUSONTHEINDIVIDUALANDCANTHEREFOREHANDLEBOTHHOMOGENEOUSANDHETEROGENEOUSPOPULATIONSTHETRANSLATIONOFTHECONCEPTUALMODELINTOANUMERICALSETTINGISUSUALLYTECHNICALLYSIMPLEANDSTRAIGHTFORWARDHENCE,CAMODELSHAVEBEENDEVELOPEDTOSIMULATEMANYBIOLOGICALSYSTEMSINTHISPAPER,ASTOCHASTICMODELBASEDONCAWENAMEITASSJCAISESTABLISHEDTOSIMULATETHETRANSMISSIONDYNAMICSOFSCHISTOSOMASISJAPONICAINTHEENDEMICAREATHESJCAMODELISUSEDTOMIMICEACHINDIVIDUAL’SSTATEANDEFFECTSOFTHESELECTEDCHEMOTHERAPYCARRIEDOUTINJIAHUVILLAGEANDTHEOUTCOMESOFSHISTOSOMIASISINTHISAREACANBEPREDICTEDBYCOMPARINGTHEOBSERVEDPREVALENCEANDINTENSITIESWITHTHEPREDICTEDDATAOF2006INJIAHUVILLAGE,THEEFFECTSOFSJCAMODELARESHOWNSATISFACTORYIIMATERIALSANDMETHODSASTUDYPOPULATIONANDSAMPLECOLLECTIONINDECEMBER2005,PEOPLELIVINGINJIAHUVILLAGEWERERECRUITEDFORA2YEARCROSSSECTIONALINVESTIGATION8LOCATEDONTHESOUTHEASTERNSHOREOFPOYANGLAKEINJIANGXIPROVINCE,THISVILLAGEWASASJAPONICUMENDEMICAREAAQUESTIONNAIREWASSUBMITTEDTOCOLLECTTHEWATERCONTACTOFEACHRESIDENTVARIABLESRECORDEDINTHEQUESTIONNAIREINCLUDEDTHETYPEOFACTIVITY,ANDTHEFREQUENCYOFWATERCONTACTANDSOONTHESCORESOFWATERCONTACTRANGEDFROM0TO80ATEACHSURVEY,TWOSTOOLSAMPLESWERECOLLECTEDFROMPARTICIPANTSATOF35DAYSINTERVALSKATOKATZTECHNIQUEWASUSEDTODETECTEGGSINTHESTOOLSANDRESULTSWERERECORDEDASEGGSPERGRAMEPG9ALLRESIDENTSFOUNDTOBEEGGPOSITIVERECEIVEDASINGLEORALDOSEOFPRAZIQUANTELOF40MG/KGBODYWEIGHTTHESELECTEDCHEMOTHERAPYWASCARRIEDOUTINJANUARYOF2006,ONEMONTHLATERTHANTHEFIRSTSURVEYTHESTUDYPOPULATIONINSJCAMODELISMADEUPOFPARTICIPANTSWITHEPGRESULTSINTHE2CONSECUTIVEYEARSTHEREARE706SUBJECTSINTHESTUDYPOPULATIONAGED574YEARS,OUTOFWHICH,134EGGPOSITIVEINDIVIDUALSANDTHEPREVALENCEWAS1898IN2005WHILE94EGGPOSITIVEINDIVIDUALSAND1331OFPREVALENCEIN2006THEGEOMETRICMEANOFEPGWAS09851548AND04721103,RESPECTIVELYFIGURE1SHOWSTHERESULTSOFTHEGEOMETRICMEANOFEPGBY8AGECATEGORIESOF10YEARSEACHINTHE2YEARSURVEYSBFRAMEWORKOFSJCAMODELTHEDEFININGCHARACTERISTICSOFCAMODELSARECELL,ITSNEIGHBOURCELLS,RULESANDTHESPATIALENVIRONMENTLATTICEEACH9781424447138/10/25002010IEEEFIGURE1RESULTSOFTHEGEOMETRICMEANOFEPGBY8AGECATEGORIESOF10YEASEACHIN2005GREYBARSAND2006WHITEBARSFIGURE2MODELLINGFLOWCHARTFORTHESIMULATIONOFTHRANMISSIONDYNAMICSOFTHEINFECTIONWITHSJAPONICUMCELL,DEFINEDBYAPOINTINAREGULARSPATIALLATTICE,CANHAVEANYONEOFAFINITENUMBEROFSTATESTHATAREUPDATEDACCORDINGTOASETOFLOGICALRULESTHESTATEOFEACHCELLATASUBSEQUENTTIMESTEPISDEPENDENTONTHECELL’SOWNSTATEAND/ORTHESTATESOFITSNEIGHBOURSATTHECURRENTTIMESTEPINOURMODEL,EACHGRIDREPRESENTSCERTAINGEOGRAPHICDISTRICTINJIAHUVILLAGEOFJIANGXIPROVINCETHEELEMENTSOFEACHINDIVIDUALAREDESCRIBEDBYPERSONWETAKEONEDAYASATIMESTEPATEACHTIMESTEP,THECHANGESOFWORMBURDENINEACHINDIVIDUALARERELATEDTOWATEREXPOSURE,NUMBEROFSCHISTOSOMESAC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