SkiptomaincontentGlobalNavigationOthersites:ECDCEuropeanAntibioticAwarenessDayESCAIDE-ScientificconferenceEurosurveillancejournalEVIP-VaccinationportalHomeAlltopics:AtoZYellowfeverFactsYellowfeverFactsThreatsandoutbreaksSurveillanceanddiseasedataPreventionandcontrolFactsaboutyellowfeverFactsheetTwitterFacebookLinkedInMail1.NameandnatureofinfectingorganismYellowfever(YF)isanAfricanmosquito-borneinfectionofprimates.ItiscausedbyavirusoftheFlavivirusgenusoftheFlaviviridaefamily.Initsnaturalhabitat,itistransmittedbetweenmonkeysbyforest-dwellingprimatophilicAedesmosquitoes.Thevirusanditsvector(Ae.aegypti)wereintroducedtotheAmericas,whereitisalsoenzooticinforesthabitat,withtheslavetrade.Sylvaticinfectionofhumansoccurswhentheyentertheforesttohunt,gatherfood,harvesttimberandsoon.Forest-infectedpersonscaninitiatehuman-to-humantransmissionifsuitableperidomesticvectorsarepresentintownsandvillages.Intheurbanenvironment,Ae.(Stegomyia)aegypti(Linn.),aforestspeciesthathasadoptedthehumandomesticenvironment,isahighlyeffectivevectorforyellowfevervirus(YFV).Thismosquitoisalsotheprincipalurbanvectorofdengueandchikungunyaviruses.Yellowfeverisdistributedinwest,centralandeastAfricaandinSouthAmerica,fromPanamatothenorthernpartofArgentina.IthasneverbeendetectedinAsia.Catastrophicepidemics,withtensofthousandsofdeaths,havebeenrecordedinruralAfrica.ThevectorAedesaegyptiwasonceendemicinEurope,andresponsibleforlargeepidemicsofYFanddengue.ThereasonforitsdisappearanceafterWorldWarIIhasneverbeenexplained.ItisstillpresentintheUnitedStatesandhasbeenrecordedin21states.Itisconceivablethatthevectorcouldbecomere-establishedandwidespreadinEurope,ashashappenedinrecentyearswithanotherputativevector,Ae.albopictus.2.ClinicalfeaturesOnsetofsymptomsissudden,usually3–5daysafterinfection.Thediseasecancauseawidespectrumofsymptoms,frommildtofatal.Inclinicalcasesthereisasuddenonsetoffeverwithsevereheadache,arthralgiasandmusclepains.Jaundicemayappearonthethirddayandindicatesapoorprognosis.Transaminaseelevationsarealso