Presentation on theme: "3- Blood Fluke Schistosoma sp."— Presentation transcript:
1 3- Blood Fluke Schistosoma sp. Schistosoma mansoni maleSchistosoma mansoni femaleSchistosoma mansoni male & femaleSchistosoma haematobium maleSchistosoma haematobium femaleEggs of Schistosoma mansoniEggs of Schistosoma haematobiumSnail of Schistosoma mansoniSnail of Schistosoma haematobiumS. mansoni cercaria
2 S. mansoni (male & female) Schistosoma mansoniS. mansoni (male)8-10 mm longhas gynaecophoric canaldorsal surface covered with tubercleS. mansoni (female)14 mm longtaller and thinnervitelline glands occupy 2/3 of the bodyS. mansoni (male & female)
3 S. mansoni (snail) Biomphalaria alexandrina S. mansoni (egg)oval with lateral spineCercaria of S. mansonielongated headbiforked tail
4 Schistosoma haematobium Eggoval with terminal spineSnailBulinus truncatus
5 veins of urinary bladder (venous plexus of urinary bladder) S. haematobiumS. mansoniveins of urinary bladder (venous plexus of urinary bladder)veins of large intestine, colon (lower mesentric vein)LocationBulinus truncatusBiomphalaria alexandrinaIntermediate hostEggs in urineEggs in stoolDiagnosisCercariaeInfective stageDirect skin penetration of cercariae during swimmingMode of transmissionUrinary BilharziasisIntestinal BilharziasisDisease
7 General Characters Tape Worms 1- All worms have long flat (no body cavity), multi-segmented body.2- The body is covered with cuticle that is provided with pores through which the worm uptakes its nutrients (no digestive system).3- All are hermaphrodites (each segment contains both male and female sexual organs).
8 4- The adult worm is divided into 3 distinct parts: a- Head or Scolex: usually with 4muscular suckers and a crownof hooks (rostellum) to attach to theintestinal wall.b- Neck Region: serves as agenerative organc- Strobilla: three types of segments(Proglottids).i. Immature: following the neck regionii. Mature: containing both sex organsand responsible for reproductioniii. Gravid: filled with fertilized eggs
9 5- Eggs: contain hexacanth embryo (oncosphere).6- All cestodes have an intermediate host except Hymenolepis nana.
10 Examples of Class Cestoda 1- Taenia sp.Taenia saginataTaenia solium2- Hymenolepis sp.Hymenolepis diminutaHymenolepis nana3- Dipylidium caninum4- Echinococcus granulosus
11 General life cycle of Cestodes 1. The adult worm matures in human intestine (final host).2. Eggs shed in feces are released into environment.3. Eggs are eaten by grazing animals (intermediate host).4. Larval forms encyst in animals’ tissue.Humans ingest encysted larvae in meat of infected animal (except in case of Echinococcus granulosus).
12 Taenia saginata (Beef Tape Worm) Length: up to 10 mTaenia saginata mature segment: nearly square, bilobed ovary, scattered testis, uterus: median tube(magnifier)Taenia saginata gravid segment longer than broad branched uterus filled with eggs(magnifier)
14 Taenia saginata Location of adult: small intestine of man Intermediate host : cattle (beef)Infective stage : Cysticercus bovisMode of transmission: eating insufficiently cooked meat containing Cysticercus bovisDiagnosis: eggs & gravid segments in stoolDisease: Taeniasis
15 Hymenolepis diminuta (Rat Tape Worm) Length: cmMature segments: Broader than long characterized by 3 testis and one ovary in each segment (magnifier)Gravid segments: Broader than long, enlarged uterus containing eggs (magnifier)
16 Hymenolepis diminutaLocation of adult: small intestine of rat occasionally manIntermediate host: rat fleaInfective stage: cysticercoidMode of transmission: ingestion of rat flea containing cysticercoidDiagnosis: eggs and gravid segments in stoolDisease: hymenolepiasis
17 Hymenolepis nana (Dwarf Tape Worm) Length: Very small mmMature segments: broader than long, characterized by 3 testis and one ovary in each segment (L.P)
18 Hymenolepis nana Location of adult: small intestine of man Intermediate host: noneInfective stage: eggsMode of transmission: eating food contaminated with eggs or autoinfectionDiagnosis: eggs in stoolDisease: Hymenolepiasis
19 Dipylidium caninum (Dog Tape Worm) Length: cmCucumber seed-like or barrel shapeMature segment: Longer than broad, 2 genital pores, testis and ovaries(magnifier)Gravid segment: Longer than broad, deformed wall, enlarged uterus filled with eggs(magnifier)
20 Dipylidium caninum Egg Packet: round to oval and containing 5-15 eggs (H.P)Scolex: showing 4 suckers and extended rostellum with four rows of hooks (L.P)
21 Dipylidium caninumLocation of adult: small intestine of dogs, occasionally manIntermediate host: dog fleaInfective stage: cysticercoidMode of transmission: ingestion of dog flea containing cysticercoidDiagnosis: egg packet in stoolDisease: Dipylidium caninum infection
23 Echinococcus granulosus Protoscolex from hydatid cyst (H.P)
24 Echinococcus granulosus Location of adult: small intestine of dogsLocation of hydatid cyst : liver, lung, CNS and bone in man, cattle and sheepIntermediate host: cattle, sheep (man is an end stage intermediate host)Infective stage (for human): eggs in fecesMode of transmission:man is infected by ingestion of eggs in dog fecesDiagnosis: identification of hydatid cyst by X-rayDisease: hydatid disease