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1、Unit21HumanBiologyEpidemicsthroughouthistoryWithrecentnewsreportsconnectedBirdFluwithakillerepidemicinthepast,JimSmithlooksthroughthehistoryofepidemicsforcluesaboutwhatthefuturemighthold.BacteriaandviruseshavebeenaroundsincethebeginningoflifeonEarthandmanyoftoday’sdiseaseshave
2、existedaslongashumanshave.Itisimportanttolookatthespreadofdiseasesthroughouthistorytodiscoverthecausesandeffectsofepidemics,andhopefully,foreseeandpreventtheminthefuture,especiallyasscientistsprovedthatBirdFluisamodernadaptationofthesamevirusoftheSpanishFlu.Oneoftheearliestepi
3、demicsonrecordhappenedabout500-550ADwhentheRomanemperoratthetimewasattemptingtorebuildtheRomanEmpire.Thisepidemic，whichwascalledJustinian’sPlague,sweptthroughNorthAfrica,theMiddleEastandEurope.Scientistsnowguessthatupto50%ofthearea’spopulationdiedfromthisepidemicmakingitoneoft
4、hemaincausesofthefalloftheRomanEmpire.Inthe1330’s,theepidemicreturned,thistimeinAsia.Thisspreadrapidlyandbecameknownas“TheBlackDeath”asonesymptomwasblackspotsonthebody.InurbanareasalloverEurope,Asia,AfricaandtheMiddleEast,uptoonehalfofthepopulationwaslosttotheBlackDeath.Anothe
5、repidemicthatspreadinsimilarconditionswastheSpanishFlu.Itstruckabout1918-1920andleftfamiliesmourningworldwide.Havingkilledupto50millionpeoplein18months,withatendencytostriketheyoungandfitratherthantheold.Morepeoplediedofthefluthandiedinthewar.Yet,somehow,itwasforgottenbyhistor
6、yuntilveryrecentlywhenSARSbecameacauseforconcern.TheSARSepidemicbeganin2002withalungdiseaseinGuangdongProvinceandspreadquicklyafterDrLiuJianjun,thecarrier,cametoHongKongandpassedthevirustopeoplewhocarriedittoCanada,VietnamandSingapore.Overninemonths,8000caseswerereportedinover
7、30countriesacrossfivedifferentcontinentsand774peopledied.AlthoughthesestatisticsaremuchlessimpressivethanthosefortheSpanishFlu,SARSwasstillveryalarmingforafewkeyreasons.Generally,SARSsymptomsincludeahighfever,bodyaches,andheadaches. However,astheillnessprogresses,mostpatientse
8、ventuallydeveloppneumonia. TheSARSvirusspreadsmainlybyclosehu
