高中英语：Malaria相关素材（牛津版选修7）VIP专享VIP免费

MalariaMalariaisaninfectiousdiseasethatkillsanaverageoftwomillionpeopleeveryyear,mostlyinthetropicsandsub-SaharanAfrica.TheWorldHealthOrganizationsaysmalariaisconstantlyoccurring–endemic–inover100countries,includingmostofsub-SaharanAfricaandNewGuinea;largeareasofSouthAsia,SoutheastAsia,Oceania,Haiti,CentralandSouthAmerica;andpartsofMexico,theDominicanRepublic,NorthAfricaandtheMiddleEast.Cause:Thediseaseiscausedbyseveralspeciesofsingle-celledparasiteofthegenusPlasmodium,anditistransmittedmostlycommonlybymosquitoes.(Malariaisrarelytransmittedthroughinfectedblood,bysharingneedlesandinchildbirth.)Infectedfemalemosquitoescarrythesporesoftheparasite.Whenamosquitobites,itcantransferthesporestoapersonthroughitssaliva.Thesporescollectintheperson'sliverandmultiplythere.Somespeciesoftheparasitecanremaindormantintheliverforseveralmonths.Fromthere,thesporesdivideandenterredbloodcells,wheretheymultiplyevenmore,sometimesburstingoutofthebloodcells.Thewavesoffevereveryfewdaysthatarecharacteristicofthediseasearecausedbytheparasitesburstingoutofbloodcellssimultaneously.Symptoms:Symptomsofmalariainclude:Headacheandfever.Chills.Muscleandjointpain.Nauseaandvomiting.Convulsions.Becausethesymptomsofmalariacanbemistakenforthoseofotherdiseases,adiagnosisrequiresabloodtest.Somespeciesoftheparasite,especiallyP.falciparum,canresultinmoreserioussymptoms,includingseizures,kidneyandlungfailure,andcoma,whichcanleadtodeath.Treatment:用心爱心专心Thetreatmentofmalariadependsonseveralthings:thespeciesofparasite,theseverityoftheinfectionandtheageofthepersoninfected.Insomepartsoftheworld,parasiteshavebecomeresistanttosomeofthedrugsusedintreatment.Almostallmalariacanbecompletelycuredifidentifiedandtreatedearly.Prevention:Themosteffectivestrategyforpreventingmalariainfectionistoavoidbeingbittenbyinfectedmosquitoes:Stayindoorsfromdusktodawn,whenmosquitoesarebitingmost.Wearlong-sleevedshirtsandlongpants.Sleepunderamosquitonetimpregnatedwithaninsecticidesuchaspermethrin.UseDEET-basedinsectrepellents.Whentravellinginareaswheremalariaisendemic,childrenareathigherriskofinfectionthanadults.Whilethereisnovaccineformalaria,thereareantimalariamedicationsavailablethatcanreducetheriskofdevelopingsymptomsofmalaria.用心爱心专心