SkipdirectlytositecontentSkipdirectlytopageoptionsSkipdirectlytoA-ZlinkSkipdirectlytoA-ZlinkSkipdirectlytoA-ZlinkTravelers'HealthFacebookTwitterLinkedInEmailSyndicateChapter4Travel-RelatedInfectiousDiseasesChapter4-Perspectives:AlternativeApproachestoRabiesImmunizationChapter4-RubellaRickettsialDiseases(IncludingSpottedFever&TyphusFeverRickettsioses,ScrubTyphus,Anaplasmosis,andEhrlichioses)WilliamL.Nicholson,ChristopherD.PaddockINFECTIOUS AGENTSRickettsialinfectionsarecausedbymultiplebacteriafromtheorderRickettsialesandgeneraRickettsia,Anaplasma,Ehrlichia,Neorickettsia,Neoehrlichia,andOrientia(Table4-19).Rickettsiaspp.areclassicallydividedintothespottedfevergroup(SFG)andthetyphusgroup,althoughmorerecentlythesehavebeenclassifiedintoasmanyas4groups.Orientiaspp.makeupthescrubtyphusgroup.TherickettsialpathogensmostlikelytobeencounteredduringtraveloutsidetheUnitedStatesincludeRickettsiaafricae(Africantick-bitefever),R.conorii(Mediterraneanspottedfever),Anaplasmaphagocytophilum(anaplasmosis),R.rickettsii(knownasbothRockyMountainspottedfeverandBrazilianspottedfever),Orientiatsutsugamushi(scrubtyphus),andR.typhi(murinetyphus).TRANSMISSIONMostrickettsialorganismsaretransmittedbythebitesorinfectiousfluids(suchasfeces)inoculatedintotheskinsfromectoparasitessuchasfleas,lice,mites,andticks.Inhalingbacteriaorinoculatingconjunctivawithinfectiousmaterialmayalsoresultininfection.ThespecificvectorsthattransmiteachformofrickettsiaearelistedinTable4-19.Transmissionofafewrickettsialdiseasesfromtransfusionofinfectedbloodproductsorbyorgantransplantationisrarebuthasbeenreported.EPIDEMIOLOGYAlltravelersareatriskofacquiringrickettsialinfectionsduringtraveltoendemicareas.Transmissionoccursthroughouttheyearbutisincreasedduringoutdooractivities.Becauseofthe5-to14-dayincubationperiodformostrickettsialdiseases,touristsmaynotexperiencesymptomsduringtheirtrip,andonsetmaycoincidewiththeirreturnhomeorwithinaweekafterreturning.Althoughthemostcommonlydiagnosedrickettsialdiseasesintravelersareusuallyint