SARS epidemiology and clinical characteristics of.docx

SARSepidemiologyandclinicalcharacteristicsofSAKSepidemiologyandclinicalcharacteristicsofSAKSepidemiologyandclinicalcharacteristicsofPapertowritenet:Keyword:SARSEpidemiologyNovember16,2002inGuangdongandinthespringof2003firstwidelypopularatypicalpneumoniaisanewinfectiousdisease,areChineseplagueareas.NowepidemiologicalandclinicalcharacteristicsofSARSreportedasfollows.1Overview1-3SARS(Atypicalpneumonias,referredtoas:pneumonia,SARSisarelativelytypicalintermsoftheformerwithoutthelatterthetypicalclinicalmanifestationsofatypicalpneumonia,hencetheterm,whilein2003thepopularatypicalpneumoniaandonpreviousclinicalSeeSARShasmanydifferentbecauseofitsacuteonset,rapidprogressoflungdisease,lunginjurywasdemonstratedbythepilotofthemultipleorgandamage,theWorldHealthOrganization(WHObetentativelyasfollows:severeacuterespiratorysyndrome(SevereAcuteRes-piratorySyndrome,SARS.SARSwithSAKSandthemaindifferencebetweenatypicalpneumoniaasdescribedinTable1Table1Typicalpneumonia,atypicalpneumonia,SARSmaindifferenceNote:R-basicreproductionnumber2Epidemiology4-122.1Features(1inwinterandspringhigh.FudanUniversitystudyfoundthat,SARSoutbreakandthemostsuitabletemperatureforthepopular17C'28C,cold,warmairsurgingduetosuddendropintemperatureledtodramaticchangesinhighconcentration;dryclimate,windspeed,theincidencerate(2-proneyoungadults,incidenceofyoungadultsaccountedfor70%,theaverageageofabout38to39years(20to83years)(3contagiousinGuangzhou,Beijing,HongKong,Hanoiandotherareashaveappearedwassuperspreaders,apersoninfectedpeopleor100people,andevensomeindividualscanbeinfectedmorethan300separateclearlytheExpertGroupbyHongKong,SingaporeearlyinfectionwereanalyzedtocalculatetheofSARS,thebasicreproductionnumber(R)gt;=3.(4highincidence;onset,rapiddevelopment;mortalityfrom6to16%higherinmenthanwomen,middle-agedthanyoung,50yearsoldmortalityrateaccountedfor64%(5significantclustersofoutbreaksofthephenomenon;suchasinhospitals,communities,schools,families,etc.oftheclusterofoutbreak.2.2pathogenApril16,2003WHOannouncedinGeneva,SARSpathogenisanewcoronavirus,named:SARSvirus.Coronavirusesaresphericalsingle-strandedRNAvirus,mostlyindiameter60'120nm,hasabagmembranespikeduetotheelectronmicroscopemountedonthediscoveryofthevirusenvelopespikeshapesimiIartothecorona,sonamedforthecoronavirusknowntohavethreetypes,coronavirusiswidelydistributedintheworld,peoplearegenerallysusceptible(infectionrateinChinaabout30%to60%,theformerSovietUnionabout53%to97%,boththeusualcausethecommoncold,chronicbronchitis,doesnotinfringethelowerrespiratorytract.SARSvirusisavariantofthecoronavirus,theUnitedStatesCharmianDelstudy,SARSRDRPvirusgeneexistson1yinthebirdcoronavirusgenesarecloselysimilar,withthethreeknowncoronavirusRf)RPgenerelationshipwasdistant;OUrscientistsfoundSARSvirusgenecivetcatsandwiIdanimalsinvivocoronavirusgenehas99.8%nucleotidesequencehomologystudieshaveshownthatSARSvirusisarecombinantandanimal-relatednewvirusisazoonoticpathogen.SomescholarsbelievethattheSARSviruseasyvariation.UniversityofHongKongSRSvirushasbeenfoundsixvariants.SARSvirusisnotresistanttoheatcold,resistancetodry.Ambientaircanonlysurvivefor3hours:roomtemperatureunder24Cvirusinplastic,glass,mosaic,metal,fabric,copypaperavarietyofsurfacescansurvive2to3daysinpatientswithdiarrheainthesputumandfecescansurvivemorethan5daysintheurinecansurviveatleast10daysinthebloodcansurviveabout15daysUV-60min,75%ethanol,chlorinedisinfectants(eg,8.45mintoinactivatethevirus,ofiodine,peraceticacidisalsosensitive;butthereisstrongresistancetogastricacid.2.3sourceofinfectioniscurrentlythesourceofinfectionandtheirsurvivalisstillnotclear.UniversityofHongKongApri116,2003announcedthattheviruscamefromanimals,andthroughcross-speciesspreadtoinfecthumans.sforwhattheanimalistobestudiedisnowtheconcernisthatcivetcatsandbirds,butwhetherthecivetcatSRSthesourceisunclear,perhapsfromanothertemporaryundiscoveredanimals,alsotherearemedicalexpertsbelievethevirusisderivedfromanimalsorfromhumanbody,orboth,hasnotbeendetermined.Today,themainsourceofinfectionisknownSARSpatients.reinfectiousthroughoutwhich,medium(about10daysafteronset)contagious：incubationperiodofinfectiousweak：nowthatwillnotinfectothersweredischargedafteraboutwhethertheSARSvirushaveobvioussymptomshavebeeninconclusive.2. 4transmissionmodeoftransmissionisstillnotclearnowthatthedropletstoclose(lmorless)spreadmainlyexpertspointedoutthatbecauseparticlesgenerallylargerdroplets,floatingintheairisnotveryfar：andaerosolparticlessmallerthancanbesuspendedintheairalongtime,sotodropletstospreadtheSARSvirus,notwithotherrespiratorypathogens,likelong-distancetransmissionthroughtheair.Inaddition,theycanstillclosecontactorthroughcontactwithSARSpatientssecretions,bodyfluidsandcontaminatedobjects,afterthenose,mouth,eyes,handsspreadofbrokenskin：bythefecal-oralroutecannotbeignored,forexample,HongKong,BlockEofAmoyGardensoutbreak,mainlyspreadthroughthesewagesystemandtheenvironmentalpolIutioncausedby,infectiondoesnotnecessarilyhavebeenincontactwithSARSpatients,and,Xiamen,HongKngDepartmentofHealthinthegarde