Influenza,Influenza,1.WhatisInfluenza?2.HowInfluenzaSpreads3.Symptoms4.Diagnosis5.Treatment6.HowtoPrevent,1.WhatisInfluenza?,Influenza(theflu)isacontagiousrespiratoryillnesscausedbyinfluenzaviruses.Itcancausemildtosevereillness,andattimescanleadtodeath.,History：2,400years,Acoldisamilderrespiratoryillnessthantheflu.Whilecoldsymptomscanmakeyoufeelbadforafewdays.Flusymptomscanmakeyoufeelquiteillforafewdaystoweeks.Coldsymptomsusuallybeginwithasorethroat,whichusuallygoesawayafteradayortwo.Nasalsymp
