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1、Unit21HumanBiologyEpidemicsthroughouthistoryWithrecentnewsreportsconnectedBirdFluwithakillerepidemicinthepast,JimSmithlooksthroughthehistoryofepidemicsforcluesaboutwhatthefuturemighthold.BacteriaandviruseshavebeenaroundsincethebeginningoflifeonEarthandmanyoft
2、oday’sdiseaseshaveexistedaslongashumanshave.Itisimportanttolookatthespreadofdiseasesthroughouthistorytodiscoverthecausesandeffectsofepidemics,andhopefully,foreseeandpreventtheminthefuture,especiallyasscientistsprovedthatBirdFluisamodernadaptationofthesameviru
3、softheSpanishFlu.Oneoftheearliestepidemicsonrecordhappenedabout500-550ADwhentheRomanemperoratthetimewasattemptingtorebuildtheRomanEmpire.Thisepidemic，whichwascalledJustinian’sPlague,sweptthroughNorthAfrica,theMiddleEastandEurope.Scientistsnowguessthatupto50%o
4、fthearea’spopulationdiedfromthisepidemicmakingitoneofthemaincausesofthefalloftheRomanEmpire.Inthe1330’s,theepidemicreturned,thistimeinAsia.Thisspreadrapidlyandbecameknownas“TheBlackDeath”asonesymptomwasblackspotsonthebody.InurbanareasalloverEurope,Asia,Africa
5、andtheMiddleEast,uptoonehalfofthepopulationwaslosttotheBlackDeath.AnotherepidemicthatspreadinsimilarconditionswastheSpanishFlu.Itstruckabout1918-1920andleftfamiliesmourningworldwide.Havingkilledupto50millionpeoplein18months,withatendencytostriketheyoungandfit
6、ratherthantheold.Morepeoplediedofthefluthandiedinthewar.Yet,somehow,itwasforgottenbyhistoryuntilveryrecentlywhenSARSbecameacauseforconcern.TheSARSepidemicbeganin2002withalungdiseaseinGuangdongProvinceandspreadquicklyafterDrLiuJianjun,thecarrier,cametoHongKong
7、andpassedthevirustopeoplewhocarriedittoCanada,VietnamandSingapore.Overninemonths,8000caseswerereportedinover30countriesacrossfivedifferentcontinentsand774peopledied.AlthoughthesestatisticsaremuchlessimpressivethanthosefortheSpanishFlu,SARSwasstillveryalarming
8、forafewkeyreasons.Generally,SARSsymptomsincludeahighfever,bodyaches,andheadaches. However,astheillnessprogresses,mostpatientseventuallydeveloppneumonia. TheSARSvirusspreadsmainlybyclosehu
