SkipdirectlytositecontentSkipdirectlytopageoptionsSkipdirectlytoA-ZlinkParasites-DiphyllobothriumInfectionSectionNavigationCDCHomeFacebookTwitterLinkedInSyndicateDiphyllobothriumlatum(andotherspecies)FAQsMinusRelatedPages OnThisPageWhatisDiphyllobothriumlatum?WhatarethesignsandsymptomsofDiphyllobothriuminfection?WhatshouldIdoifIthinkImightbeinfected?HowisinfectionwithDiphyllobothriumdiagnosed?IsmedicationavailabletotreatinfectionwithDiphyllobothriuminfection?HowdidIgetinfectedwithDiphyllobothrium?Whoisatgreatestriskofinfection?HowcanIpreventDiphyllobothriuminfection?WhatisDiphyllobothriumlatum?Diphyllobothriumlatumandrelatedspecies(thefishorbroadtapeworm),thelargesttapewormsthatcaninfectpeople,cangrowupto30feetlong.SeveralotherDiphyllobothriumspeciesinfecthumans,butlessfrequently.WhatarethesignsandsymptomsofDiphyllobothriuminfection?Mostinfectionsareasymptomatic.Howeversymptomscanincludeabdominaldiscomfort,diarrhea,vomiting,andweightloss.VitaminB12deficiencyleadingtoperniciousanemiamayoccur.Complicationsincludeintestinalobstructionandgallbladderdiseasecausedbymigrationofproglottids.WhatshouldIdoifIthinkImightbeinfected?Seeyourhealthcareprovider.HowisinfectionwithDiphyllobothriumdiagnosed?Diagnosisismadebyidentificationofeggsorsegmentsofthetapeworminastoolsamplewithamicroscope.Eggsareusuallynumerous,butmorethanonestoolsamplemaybeneededtofindthem.IsmedicationavailabletotreatinfectionwithDiphyllobothriuminfection?Yes,safeandeffectivemedicationsareavailabletotreatDiphyllobothriuminfection(praziquantelorniclosamideareusedmostoften).HowdidIgetinfectedwithDiphyllobothrium?Yougotinfectedbyeatingraworundercookedfish.Examplesoffishincludesalmon,trout,perch,walleyedpike,andotherspecies—usuallyfreshwaterfish.SomefishsuchassalmonliveinbothfreshandsaltwaterandcanharborDiphyllobothriumlarvae.Lightlysalted,smoked,orpickledfishalsomaycontaininfectiousorganisms.Whoisatgreatestriskofinfection?DiphyllobothriuminfectiongenerallyoccursintheNorthernHemisphere(Europe,newlyindependentstates