![Page 1: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/1.jpg)
Introduction to tromatodesIntroduction to tromatodes
Phylum PlatyhelminthesClass TrematodaOrder Digenea
![Page 2: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/2.jpg)
MorphologyMorphology
• Adult worm– Flattened (flatworm) and leaf like– Sucker: oral & ventral (fluke)– Body wall: musculo-tegumental sac– Parenchyma (structure between body wall and i
nternal organs): connective tissue fibers, cells and space between them
![Page 3: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/3.jpg)
![Page 4: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/4.jpg)
– Digestive tract: not intact
i.e. no anal opening, caecum– Reproductive system: hermaphrodite (monoeci
ous) exception of schistosome– Muscular system– Nervous system– Excretory system
![Page 5: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/5.jpg)
• Egg
– Size divergent
– Ovoid
– Operculum (exception of that of schistosome)
– Content: ovum , vitelline cells, or miracidium
![Page 6: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/6.jpg)
Egg of Clonorchis sinensis
![Page 7: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/7.jpg)
Egg of Paragonimus westermani
![Page 8: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/8.jpg)
Egg of Fasciolopsis buski
![Page 9: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/9.jpg)
S. japonicum S. Mansoni S. haematobium
Schistosome egg
![Page 10: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/10.jpg)
Features Reflecting Features Reflecting Adaptation to ParasitismAdaptation to Parasitism
• Organs of attachment highly developed
• Retardation of digestive system
• Highly developed reproductive system
![Page 11: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/11.jpg)
Life CycleLife Cycle
• Complex • Alteration of generation
sexual generation and asexual generation alter in the life cycle of parasite
• Asexual multiplication in larval stage in snail host• Multiple hosts transfer and having reservoir hosts
in majority• Water environment is essential
![Page 12: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/12.jpg)
Important SpeciesImportant Species
• Liver fluke: Clonorchis sinensis
• Intestinal fluke: Fasciolopsis buski
• Lung fluke: Paragonimous westermani
P. skrjabini
• Blood fluke: Schistosoma spp.
![Page 13: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/13.jpg)
The Liver FlukeThe Liver Fluke肝吸虫肝吸虫
Clonorchis sinensisClonorchis sinensis中华支睾吸虫中华支睾吸虫
![Page 14: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/14.jpg)
Introduction Introduction
• Parasite of biliary passage
• Cause “clonorchiasis”
• A common trematode in Far East
• First report
1874 oversea Chinese in India
![Page 15: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/15.jpg)
MorphologyMorphology
• Adult worm
– Size & Shape
like the seed of sunflower
– Sucker: oral = ventral
– 2 dendritic testes lie in tandem to each other in t
he posterior region (clonorchis)
![Page 16: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/16.jpg)
Adults of Clonorchis sinensis
![Page 17: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/17.jpg)
![Page 18: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/18.jpg)
![Page 19: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/19.jpg)
Cross section of Clonorchis sinensis adult in the hepatic bile duct
![Page 20: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/20.jpg)
• Egg
– Size: smallest
– Shape: just like sesame
– Color: yellowish brown
– Operculum distinct: shoulder, knob
– Content: miracidium
![Page 21: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/21.jpg)
Clonorchis sinensis egg. These are small operculated eggs. Size 27 to 35 µm by 11 to 20 µm. The operculum, at the smaller end of the egg, is convex and rests on a visible "shoulder". At the opposite (larger, abopercular) end, a small knob or hooklike protrusion is often visible (as is the case here). The miracidium is visible inside the egg.
![Page 22: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/22.jpg)
Egg of Clonorchis sinensis
![Page 23: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/23.jpg)
Life cycle of Clonorchis sinensis
![Page 24: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/24.jpg)
Life CycleLife Cycle
• A model pattern of trematode
• Main points
– Definitive host: human being
– Reservoir host: dog, cat, etc.
– Residing: hepatic bile duct
– Discharge of eggs with feces
![Page 25: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/25.jpg)
– Hatching in the host small intestine
– 2 intermediate host
I: snails, such as Bithynia,Parafossarulus
II: freshwater fishes, such as Cyprinus
– 2 generation of asexual proliferation
– Infective stage: metacercaria in fish
– Infective route: oral consumption
![Page 26: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/26.jpg)
PathogenesisPathogenesis
• Due to adult worm
• Mechanism
– Mechanical: sucker
– Chemical: excretions, secretions, metabolite
– Biological: nutrition deprivation
![Page 27: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/27.jpg)
• Pathological process
– Inflammation Proliferation
ThickeningOcclusion
– Extensive involvementFibrosis of the liver
![Page 28: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/28.jpg)
Clinical ManifestationsClinical Manifestations
• Acute stage: allergic reaction
• Chronic stage: functional impairment of liver (Cholangitis, Cholecystitis, Bile stone, Jaundice, etc)
• Advanced stage: portal cirrhosis & malignancy
![Page 29: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/29.jpg)
Laboratory DiagnosisLaboratory Diagnosis
• Etiological
– Examination of egg in feces by sedimentation
method
– Duodenal aspiration
• Immunological
– ELISA to detect antiboby or antigen
![Page 30: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/30.jpg)
EpidemiologyEpidemiology
• Distribution
– Far East
(China, South Korea, Japan, etc.)
– 24 provinces in China
(Guangdon: 5 million infected etc.)
![Page 31: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/31.jpg)
![Page 32: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/32.jpg)
Endemic FactorsEndemic Factors
• Source of infection: mainly wild carnivores
• I,II intermediate host in the same water-
field
• Mode of fish breeding
• Dinning habit & Customs
![Page 33: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/33.jpg)
Principle of ControlPrinciple of Control
• Cure patients & carrier
• praziquantel:25mg/kg, tid, 2 days
• Control reservoir host
• Carry out scientific fish-breeding
• Hygienic educationnot eating raw or undercooked fishes
![Page 34: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/34.jpg)
Paragonimus westermaniParagonimus westermani卫氏并殖吸虫卫氏并殖吸虫
Paragonimus skrjabiniParagonimus skrjabini(Paragonimus szechuanensis)(Paragonimus szechuanensis)
斯氏狸殖吸虫斯氏狸殖吸虫
![Page 35: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/35.jpg)
The Lung FlukeThe Lung Fluke
• Genus paragonimus
• Zoonotic parasite (cause zoonosis)
• Animal infection> human infection
• 2 major species in China
![Page 36: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/36.jpg)
IntroductionIntroduction
• Pathogen of lung disease
• Endemic hemoptysis
• Favorite lodging site: lung
• Ectopic site: brain, abdomen, muscle, etc.
![Page 37: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/37.jpg)
MorphologyMorphology
• Adult worm
• Body thick (a half piece of a bean grain)
• Tegument: spinous
• Sucker: oral = ventral
• Parallel arrangement of reproductive organlobular testes (posterior)lobular ovary & uterus (anterior)
![Page 38: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/38.jpg)
![Page 39: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/39.jpg)
Cross section of lung containing adult Paragonimus westermani.
![Page 40: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/40.jpg)
• Egg
– Median size, ovoid (water pot)
– Golden yellow
– Distinctive & wide operculum
– Contain 1 germ cell & several yolk cells
![Page 41: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/41.jpg)
Egg of Paragonimus westermani.
![Page 42: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/42.jpg)
Life cycle of Paragonimus westermani.
Crab or crayfish
![Page 43: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/43.jpg)
Life cycleLife cycle
• Definitive host: human being
• Reservoir host: carnivorous animals
• Habitation: lung & ectopic site
• Intermediate host:I: Melania snailsII: stream crabs, crayfish
![Page 44: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/44.jpg)
• Infective stage: metacercaria
• Infective mode: oral route, may via paratenic host (swine)
• Migration & Preadult wondering
• Ectopic parasitism: cerebral, abdominal,etc.
• Eggs discharged with sputum & feces
• 3 generation of asexual multiplication
![Page 45: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/45.jpg)
![Page 46: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/46.jpg)
PathogenesisPathogenesis
• Stage take responsibility: adult & preadult
• Pathological processes
– Abscess stage( 脓肿期 )
– Cystic stage( 囊肿期 )
– Scar formation stage( 纤维疤痕期 )
![Page 47: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/47.jpg)
• 4 clinical types– Thoracic (pulmonary type):chest pain, coughin
g, blood-tinged sputum(hemoptysis)– Abdominal (hepatic type):hepatomegaly– Cranial type: dizzy, headache, epilepsy– Musculocutaneous type: migratable subskin no
dule
![Page 48: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/48.jpg)
Laboratory diagnosisLaboratory diagnosis
• Disease history + physical examination
• Etiological diagnosiseggs in sputum or feces by sedimentation
• Immunological diagnosisfor ectopic infections
![Page 49: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/49.jpg)
EpidemiologyEpidemiology
• Globalmain continent except Europe
• China 23 provinces
![Page 50: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/50.jpg)
Paragonimus westermani infection occurs in Asia (especially in China (Taiwan), Corea, India, Japan, Laos, Philippines, Sri Lanka, Thailand, Viet-Nam), Central-West Africa, South America (Ecuador, Peru Venezuela).
![Page 51: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/51.jpg)
Principle of controlPrinciple of control
• Treat patient: praziquantel
• Hygienic education
• Social construction, economic refinement
![Page 52: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/52.jpg)
The Ginger FlukeThe Ginger Fluke姜片虫姜片虫
Fasciolopsis buskiFasciolopsis buski布氏姜片吸虫布氏姜片吸虫
Intestinal flukeIntestinal fluke肠道吸虫肠道吸虫
![Page 53: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/53.jpg)
MorphologyMorphology
• Adult worm
– Like a ginger piece
– Big muscular trematode
– Have strong suckers , ventral >> oral
![Page 54: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/54.jpg)
Adult fluke of Fasciolopsis buski The adult flukes range in size: 20 to 75 mm by 8 to 20 mm
![Page 55: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/55.jpg)
Fasciolopsis buskii adult worm
![Page 56: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/56.jpg)
• Egg
– Biggest
– Ovoid
– Minute operculum
– Yellowish
– Germ cell inclusions
![Page 57: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/57.jpg)
F.buski eggs are released in feces unembryonated. The operculated eggs are oval, brown and measure 130-150 by 78-100 um
![Page 58: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/58.jpg)
Life cycle of Fascilopsis buski
![Page 59: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/59.jpg)
![Page 60: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/60.jpg)
Life CycleLife Cycle
• Definitive host: human being
• Reservoir host: swine, etc.
• Intermediate host: Planorbis snails
• Aquatic plant vectors: caltrops, water chestnut, etc.
• Habitation: small intestine
![Page 61: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/61.jpg)
• Infective stage: metacercaria
• Infective route: oral
• Developmental stages: as Paragonimus
• 3 generation of asexual proliferation
![Page 62: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/62.jpg)
Pathogenesis FactorsPathogenesis Factors
• Traumatic (suckers)
• Obstructive (due large size)
• Toxic (excretion, secretion, metabolite)
![Page 63: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/63.jpg)
Clinical ManifestationClinical Manifestation
• Abdominal pain
• Acute intestinal obstruction
• Anemia
• Generalized edema
![Page 64: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/64.jpg)
Laboratory DiagnosisLaboratory Diagnosis
• Examination of egg in feces by sedimentation method
![Page 65: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/65.jpg)
EpidemiologyEpidemiology
• Aquatic plant raising districts
![Page 66: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/66.jpg)
Fasciolopsis buski: is endemic in China (Taiwan), South-East Asia,
Malaysia and India.
![Page 67: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/67.jpg)
Principle of ControlPrinciple of Control
• Drug for treatment: praziquantel
• Water & nightsoil control; Scientific swine raising
• Hygienic education
![Page 68: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/68.jpg)
IntroductionIntroduction
• 6 species of human schistosomes– Schistosoma japonicum– S. mansoni– S. haematobium– S. intercalatum– S. mekongi– S. malayi
![Page 69: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/69.jpg)
Schistosoma japonicumSchistosoma japonicum
日本血吸虫
![Page 70: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/70.jpg)
Distribution and Epidemic SituationDistribution and Epidemic Situation
• Worldwide– 200 million of population infected in 74
countries(S.m. 55; S.h. 55; S.j. 4; S.i. 10; S.me. 2; S.ma. 1)
• China– 11 million in 12 provinces 0.7 million in 8
provinces
50 years
![Page 71: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/71.jpg)
Before control After control (1996)
Regional distribution of S. japonicum infection in China
![Page 72: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/72.jpg)
Morphology Morphology
• Difference from other trematodes
– Dioecious adults
– Non-opeculate egg
– Bifurcated (forked) cercaria invades the final ho
st by skin
– Adults parasitize blood vessels
![Page 73: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/73.jpg)
• Adult
– Male (15 mm length) < female (22 mm)
– Oral sucker < ventral sucker
– 2 paralleled guts form a blind caecum in the pos
terior ends
– 7 testes in male and single ovary with a tubule
uterus in female
– Gynecophoric canal (male) in which female rep
ose
![Page 74: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/74.jpg)
![Page 75: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/75.jpg)
![Page 76: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/76.jpg)
![Page 77: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/77.jpg)
• Egg
– Ovoid and non-opeculate
– 74~106 m × 55~80 m
– Contains one miracidium
– Bear a minute lateral knob.
• Miracidium
• Cercaria
![Page 78: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/78.jpg)
S. japonicum S. Mansoni S. haematobium
Schistosome egg
![Page 79: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/79.jpg)
Schistosome miracidium
![Page 80: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/80.jpg)
Schistosome cercaria
![Page 81: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/81.jpg)
Life CycleLife CycleEggs discharged fresh water (hatch) miracidia pe
netrate oncomelania(I.H.)mother sporocysts (multiplica
tion) daughter sporocysts (multiplication) cercariae
(infective form) skin penetration of D.H. schistosomul
um right heart lungs left heart
systemic circulation portal system pairing and sexu
al maturation mesenteric veins lay eggs eggs develo
p and live in tissue for 21 days( 23% in liver tissue, 60% in int
estinal tissue, 17% discharged)
![Page 82: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/82.jpg)
![Page 83: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/83.jpg)
Cercarial dermatisis due to avian schistosome
![Page 84: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/84.jpg)
Main Points of Life CycleMain Points of Life Cycle
• Residing site: mesenteric vein
• I.H.(Only one): Oncomelania hupensis
• No metacercaria and redia stage
• Two generation of sporocyst
• Infective stage: cercaria
• Route of infection: skin penetration
![Page 85: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/85.jpg)
Adult of Schistosome in mesenteric veins of hamster
![Page 86: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/86.jpg)
Onchomelania hupensis
![Page 87: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/87.jpg)
Skin penetration of cercaria first
appearance of eggs: 30~35 days
Life spans in human: 4~5 years, longest: 35
years
![Page 88: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/88.jpg)
• Tissue egg
– The egg which can develop and live in tissue
• Significance of tissue egg
– Major pathogenic stage, inflammation and
granuloma around the egg
– Diagnosis and evaluation of therapeutic
efficacy
![Page 89: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/89.jpg)
ImmunityImmunity
• Concomitant immunity
– Host carrying an initial infection of adult schist
osomes shows the protection to a cercarial chall
enge infection ( 攻击性感染) and this protecti
ve immunity will disappear with eradication of
schistosomes in the host
![Page 90: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/90.jpg)
• Immuno-evasion: It’s an ability by which the schistosome adult can evade the host immune response. The possible mechanism of evasion.– Acquire host antigen on it surface
– Host-like antigen produced by parasite
– Changing of tegument very quickly
– Parasite may inactivate or down-regulate immune effectors
![Page 91: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/91.jpg)
PathogenesisPathogenesis
Schistosomiasis at each stage of the life cycle in human body
• Cercaria (skin-penetration)– Dermatitis
• Schistosomula (migration)– Larva migrans
• Adult: (immunocomplex)– Immuno-nephropathy
![Page 92: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/92.jpg)
• Tissue egg: principal pathogenic stage
Miracidium within eggSEASensitization of T Cell
Th1IL-2, INF-, TNF activate macrophage, induce cell-mediated immunity
Th2IL-4, IL-5 stimulate IgE production or eosinophilia
inflammation and granuloma fibrosis portal hypertension
intestinal polyp
![Page 93: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/93.jpg)
Clinical FormClinical Form
• Acute schistosomiasis– Fever, diarrhea, abdominal pain, enlargement of liver o
r spleen
• Chronic schistosomiasis– asymptomatic or diarrhea, abdominal pain, enlargement
of liver or spleen
• Advanced schistosomiasis– Ascites; splenomegaly;collateral circulation; dwarfism;
– Ectopic lesion: encephalitis; focal epilepsy
![Page 94: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/94.jpg)
Advanced schistosomiasis patient with portal hypertension and ascites
![Page 95: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/95.jpg)
A patient with S. j has marked ascites, splenomegaly,umbilical hernia and distended superficial abdominal veins.
![Page 96: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/96.jpg)
DiagnosisDiagnosis
• Parasitological diagnosis (etiological, definitive diagnosis)– Demonstrating eggs by stool examination– Stool examination after concentration
(sedimentation)– *Miracidium-hatching from eggs– Rectal biopsy — eggs-demonstration
![Page 97: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/97.jpg)
Miracidium-hatching from eggsMiracidium-hatching from eggs
Necessity: tissue ova;
low egg burden due to mass treatment
Possibility:• Hatch quickly (T:25; limpid water; free of
Cl2;light; pH=6.8-7.8)
• Three tropism:limpidity, phototrophic, ascendancy• Swimming in a zigzag way
![Page 98: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/98.jpg)
• Immunodiagnosis (indirect diagnosis)
– Detection of antibodies in serum, urine, saliva b
y ELISA, but is impossible to distinguish curre
nt infection from past infection.
– Detection of antigens (circulation anodic and ca
thodic antigen)
![Page 99: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/99.jpg)
• Combined diagnosis: including
epidemiological antecedent, symptoms and
signs, parasitological and immunological
examination.
![Page 100: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/100.jpg)
TreatmentTreatment
Praziquantel 60 mg/kg divided in 3 doses.
![Page 101: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/101.jpg)
Factors of Transmission and Factors of Transmission and PreventionPrevention
• Factors– Source of infection: patients and reservoir host– Intermediate host: Oncomelania– Contact with cercaria-infected water
![Page 102: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/102.jpg)
• Preventive measures– Detection and treatment of patients and reservoir h
ost
– Elimination or control of oncomelania
– Protection of susceptible population and avoidance of contact with cercaria-infected water
– Prevention of water contamination by human night soil
![Page 103: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/103.jpg)
Distinguishing of 3 major Distinguishing of 3 major schistosomesschistosomes
(see page 54, Table 3-1)
![Page 104: Introduction to tromatodes Phylum Platyhelminthes Class Trematoda Order Digenea](https://reader035.vdocuments.site/reader035/viewer/2022081419/56649cab5503460f9496bc2a/html5/thumbnails/104.jpg)