Intestinal Taeniasis

Intestinal TaeniasisIntroduction-The main helminths which cause git infections are cestodes, Trematodes and nematodes- Intestinal Cestode - T. Saginata and T. Solium (cause intestinal taeniasis)- Intestinal Trematodes- intestinal flukes, blood flukes- Intestinal Nematode - ascaris, trichurisIntestinal Cestode infectionsCestodes are long,segmented, flattened dorsoventrallyBased on Habitat 2 grps1. Intestinal Cestode - Here the adult worms inhabit the human intestineEg:T.solium, T.saginata2. Somatic / Tissue Cestode- here larvae are found in human muscles of organsEg: T.solium , echinococcus speciesINTESTINAL TAENIASIS IN DETAILPathogenic species- T.saginata, T.soliumMorphological forms-3 forms: adult form, larval form, eggs* 1. Adult form- long segmented ,3 parts - head or scolex, neck, strobila or bodyThe strobila consists of 3 segments :immature, mature and gravid proglottidsScolex of Taenia : Have 4 cup like muscular suckers for attachmentsIn T. solium scolex has a beak called Rostellum It has 2 rows of hooklets, therefore known as "Armed tapeworm"Hooklets on rostellumSuckerNeck regionImmatureproglottidsMatureproglottideStrobilaGravidproglottidsFlg.46.11 Adult worm of cestode (schematk diagram).2. Eggs -- formed following fertilisation- eggs fills the gravid- they are round to oval in shape surrounded by radially striated embryophore.Note - in T. saginata and T.solium, , 3 pairs of hooklets surround the embryophore.OperculumEgg shellThree pairs of hookletsEmbryophoreEmbryoKnobFigs 46.2A to C:Schematic diagrams of eggs of cestodes: A. D. latum;B. Other cestodes; C Other cestodes after the loss of egg shelt3. Larva- this stage is called cysticercus,for T.saginata - cysticercus bovisT.solium -cysticercus cellulosaeDifference b/w T.Saginata & T.Solium WOFFERaatranoutarsuchersEveryNo rostellumNo hookletsProglottictsNo.UterusLobesVaginal sphincterExpulsion ofsegmentsLarvaEgdTaenia saginataTaenia soliumIntestinal taeniasisIntestinal taeniasis and cysticercosisDefinitive hosts-man.Intestinal taeniasis- definitive host-intermediate host-cattleman, intermediate host-pig.Infective form-larvacysticercosis- manIntestinaltaeniasis-larva,Diagnostic form- egg infecescysticercosis-eggTransmission-Taeniasis- eggs. cysticercosis- larvacontaminated beef.Taeniasis- contaminated pork.cysticercosis- contaminated foodand waterMnemonic : Sagina thathante beef roast!(T.saginata beef/ cattle is intermediate host)Life Cycle®UN*Two hosts : man - definitive host, cattle or pig- intermediate host *Transmission - man acquires the infection from undercooked beef or pork containingcysticercus bovis/ cysticercus cellulosae which is the infective form.* In the HUMAN GIT it develops into adult form and undergoes fertilisation therein to releaseeggs which are then released into faeces.Intermediate hosts : Eggs are ingested by cattle/ pig while grazing the field* In case of pigs , when these eggs are ingested by them the eggs penetrate their intestinal wall-> migrates into skeletal muscle through blood -> transforms into larvae. ( CYSTERICUS)This gets encysted and deposits as cysts.CYSCTICERCOSISMan gets infected by drinking water or eating uncooked vegetables infected with egg.This can develop in any organ, especially the subcutaneous tissue and muscles.Neurocysticcrcosis- involves the nervous system, most serious.NOTE :Intestinal taeniasis caused by : T.saginata and T. soliumCysticercosis caused by: T. Solium onlyClinical features* most of them are asymptomaticMild abdominal pain, nausea, loss of appetite*Perianal discomfort or pruritis*Epileptic attacks in the brain - caused by cysticercosis cellulosae.Lab diagnosis1. Stool examination : wet mount examination to detect taenia eggs and sometimes proglottids- Saline mount : eggs are bile stained and are golden brown- lodine mount : nuclear details of eggs are obtained.- Scolex can be very rarely detected in faeces ; scolex of T.saginata - 4 cusps; scolex of T.Solium - Rostellum + 2 pairs of hookletsSaginata - acid fast Eggs of Taenia underSaline Mount3rd picture shows 4hooks clearlyDoes Ziehl-Neelsen staining diffentiateTaeniaeggs found in human stoolfrom T.solium to T. saginata?Taenia sollureTeenia againstaShape sphericalShape: OvalEmbryophore: Non-acid fastEmbryophore: Acid-fast (red)Eggs of Taenia in lodine mount4 Proglottid found in stool sampleINSTITUTO NACIONALDE EASEPARASIFOLOGIABoyahd P.C. Columbia19Scolex can be very rarely detected in fecesSCONEScolex of>T saginataScolex ofT SoliumRostellum and2 pairs of hooklets present32. Concentration Techniques - formal ether sedimentation. The sediment which consists ofeggs is then used to prepare a wet mount3. Anal swabs are also used to collect fecal matter.4. Taenia Specific Antigen Detection / Coproantigen - ELISA (disadvantage - cannotdifferentiate the taenia species)Highly sensitiveCarrier detection5. Molecular Methods - PCR targeting the mitochondrial DNA, followed by sequencing(advantage - can differentiate b/w taenia species)Treatment- DOC : Praziquantel (single dose of 10mg/kg)- Niclosamide (2g) can also be given (not widely used in India)