SkipdirectlytositecontentSkipdirectlytopageoptionsSkipdirectlytoA-ZlinkSkipdirectlytoA-ZlinkSkipdirectlytoA-ZlinkLassaFeverSectionNavigationCDCHomeFacebookTwitterLinkedInSyndicateTransmissionFrenchMinusRelatedPagesThereservoir,orhost,ofLassavirusisarodentknownasthe“multimammaterat”(Mastomysnatalensis).Onceinfected,thisrodentisabletoexcretevirusinurineforanextendedtimeperiod,maybefortherestofitslife.Mastomysrodentsbreedfrequently,producelargenumbersofoffspring,andarenumerousinthesavannasandforestsofwest,central,andeastAfrica.Inaddition,Mastomysreadilycolonizehumanhomesandareaswherefoodisstored.AllofthesefactorscontributetotherelativelyefficientspreadofLassavirusfrominfectedrodentstohumans.TransmissionofLassavirustohumansoccursmostcommonlythroughingestionorinhalation.Mastomysrodentsshedthevirusinurineanddroppingsanddirectcontactwiththesematerials,throughtouchingsoiledobjects,eatingcontaminatedfood,orexposuretoopencutsorsores,canleadtoinfection.BecauseMastomysrodentsoftenliveinandaroundhomesandscavengeonleftoverhumanfooditemsorpoorlystoredfood,directcontacttransmissioniscommon.Mastomysrodentsaresometimesconsumedasafoodsourceandinfectionmayoccurwhenrodentsarecaughtandprepared.Contactwiththevirusmayalsooccurwhenapersoninhalestinyparticlesintheaircontaminatedwithinfectedrodentexcretions.Thisaerosolorairbornetransmissionmayoccurduringcleaningactivities,suchassweeping.Directcontactwithinfectedrodentsisnottheonlywayinwhichpeopleareinfected;person-to-persontransmissionmayoccurafterexposuretovirusintheblood,tissue,secretions,orexcretionsofaLassavirus-infectedindividual.Casualcontact(includingskin-to-skincontactwithoutexchangeofbodyfluids)doesnotspreadLassavirus.Person-to-persontransmissioniscommoninhealthcaresettings(callednosocomialtransmission)whereproperpersonalprotectiveequipment(PPE)isnotavailableornotused.Lassavirusmaybespreadincontaminatedmedicalequipment,suchasreusedneedles.RelatedLinksRodentsArenavirusesPagelastreviewed:March25,2014Contentsource:CentersforDiseaseContr