TrichinellaspiralisFromWikipedia,thefreeencyclopediaJumptonavigationJumptosearchSpeciesofroundwormTrichinellaspiralisScientificclassificationKingdom:AnimaliaPhylum:NematodaClass:EnopleaOrder:TrichocephalidaFamily:TrichinellidaeGenus:TrichinellaSpecies:T. spiralisBinomialnameTrichinellaspiralis(Owen,1835)Trichinellaspiralisisaviviparous[1]nematodeparasite,occurringinrodents,pigs,bears,hyenasandhumans,andisresponsibleforthediseasetrichinosis.Itissometimesreferredtoasthe"porkworm"duetoitbeingtypicallyencounteredinundercookedporkproducts.Itshouldnotbeconfusedwiththedistantlyrelatedporktapeworm.Contents1Description1.1Morphology2Lifecycle2.1Nursecellformation3Symptoms4Diagnosisandtreatment5Preventionandcontrol6Economicimpact7Genome8Seealso9References10Furtherreading11ExternallinksDescription[edit]Trichinellaspecies,thesmallestnematodeparasiteofhumans,hasanunusuallifecycle,andareoneofthemostwidespreadandclinicallyimportantparasitesintheworld.[2]Thesmalladultwormsmatureinthesmallintestineofadefinitivehost,suchasapig.Eachadultfemaleproducesbatchesoflivelarvae,whichborethroughtheintestinalwall,enterstheblood(tofeedonit)andlymphaticsystem,andarecarriedtostriatedmuscle.Onceinthemuscle,theyencyst,orbecomeenclosedinacapsule.Humanscanbecomeinfectedbyeatinginfectedpork,horsemeat,orwildcarnivoressuchasfox,cat,hyenaorbear.[2]Morphology[edit]MalesofT.spiralismeasurebetween1.4and1.6 mmlong,andaremoreflatanteriorlythanposteriorly.Theanuscanbefoundintheterminalend,andtheyhavealargecopulatorypseudobursaoneachside.[2]ThefemalesofT.spiralisareabouttwicethesizeofthemales,andhaveananusfoundterminally.Thevulvaislocatedneartheesophagus.Thesingleuterusofthefemaleisfilledwithdevelopingeggsintheposteriorportion,whiletheanteriorportioncontainsthefullydevelopedjuveniles.[2]Lifecycle[edit]Trichinellaspiraliscanlivethemajorityofitsadultlifeintheintestinesofhumans.Tobeginitslifecycle,T.spiralisadultsinvadetheintestinalwallofapig,andproducelarvaethatinvadethepig'smuscles.Thelarvalformsareencapsulatedasa