Unit9ReadingandIntegratingBackground:THEDISEASEWhatisSARS?Severeacuterespiratorysyndrome(SARS)isaviralrespiratoryillnessthatwasrecognizedasaglobalthreatinMarch2003,afterfirstappearinginSouthernChinainNovember2002.WhatarethesymptomsandsignsofSARS?Theillnessusuallybeginswithahighfever(measuredtemperaturegreaterthan100.4°F[>38.0°C]).Thefeverissometimesassociatedwithchillsorothersymptoms,includingheadache,generalfeelingofdiscomfort,andbodyaches.Somepeoplealsoexperiencemildrespiratorysymptomsattheoutset.Diarrheaisseeninapproximately10percentto20percentofpatients.After2to7days,SARSpatientsmaydevelopadry,nonproductivecoughthatmightbeaccompaniedbyorprogresstoaconditioninwhichtheoxygenlevelsinthebloodarelow(hypoxia).In10percentto20percentofcases,patientsrequiremechanicalventilation.Mostpatientsdeveloppneumonia.WhatisthecauseofSARS?SARSiscausedbyapreviouslyunrecognizedcoronavirus,calledSARS-associatedcoronavirus(SARS-CoV).ItispossiblethatotherinfectiousagentsmighthavearoleinsomecasesofSARS.HowisSARSspread?TheprimarywaythatSARSappearstospreadisbycloseperson-to-personcontact.SARS-CoVisthoughttobetransmittedmostreadilybyrespiratorydroplets(dropletspread)producedwhenaninfectedpersoncoughsorsneezes.Dropletspreadcanhappenwhendropletsfromthecoughorsneezeofaninfectedpersonarepropelledashortdistance(generallyupto3feet)throughtheairanddepositedonthemucousmembranesofthemouth,nose,oreyesofpersonswhoarenearby.Thevirusalsocanspreadwhenapersontouchesasurfaceorobjectcontaminatedwithinfectiousdropletsandthentoucheshisorhermouth,nose,oreye(s).Inaddition,itispossiblethatSARS-CoVmightbespreadmorebroadlythroughtheair(airbornespread)orbyotherwaysthatarenotnowknown.Whatdoes"closecontact"mean?ClosecontactisdefinedashavingcaredfororlivedwithapersonknowntohaveSARSorhavingahighlikelihoodofdirectcontactwithrespiratorysecretionsand/orbodyfluidsofapatientknowntohaveSARS.Examplesincludekissingorembracing,sharingeatingordrinkingutensils,closeconversation(within3feet),physicalexamination,andanyotherdirectphysicalcontactbetweenpeople.Closecontactdoesnotincludeactivitiessuchaswalkingbyapersonorbrieflysittingacrossawaitingroomoroffice.IfIwereexposedtoSARS-CoV,howlongwouldittakeformetobecomesick?ThetimebetweenexposuretoSARS-CoVandtheonsetofsymptomsiscalledthe"incubationperiod."TheincubationperiodforSARSistypically2to7days,althoughinsomecasesitmaybeaslongas10days.Inaverysmallproportionofcases,incubationperiodsofupto14dayshavebeenreported.HowlongisapersonwithSARSinfectioustoothers?AvailableinformationsuggeststhatpersonswithSARSaremostlikelytobecontagiousonlywhentheyhavesymptoms,suchasfeverorcough.Patientsaremostcontagiousduringthesecondweekofillness.However,asaprecautionagainstspreadingthedisease,CDCrecommendsthatpersonswithSARSlimittheirinteractionsoutsidethehome(forexample,bynotgoingtoworkortoschool)until10daysaftertheirfeverhasgoneawayandtheirrespiratory(breathing)symptomshavegottenbetter.IsapersonwithSARScontagiousbeforesymptomsappear?Todate,nocasesofSARShavebeenreportedamongpersonswhowereexposedtoaSARSpatientbeforetheonsetofthepatient'ssymptoms.WhatmedicaltreatmentisrecommendedforpatientswithSARS?CDCrecommendsthatpatientswithSARSreceivethesametreatmentthatwouldbeusedforapatientwithanyseriouscommunity-acquiredatypicalpneumonia.SARS-CoVisbeingtestedagainstvariousantiviraldrugstoseeifaneffectivetreatmentcanbefound...
