This document summarizes key information about trematodes (flukes). It describes their morphology, lifecycles, pathogenic species and the diseases they cause. Trematodes have oral and ventral suckers, and are hermaphroditic except for schistosomes. Their complex lifecycles involve snail and fish/crab intermediate hosts. Major pathogenic genera include Schistosoma, Fasciola, Clonorchis and Paragonimus. Schistosomiasis causes urogenital and hepatosplenic disease. Fascioliasis results in liver damage. Clonorchiasis and paragonimiasis can lead to cholangiocarcinoma and pulmonary complications respectively

2. Trematodes : Flukes
• 1) INTRODUCTION
• Unsegemented helminthes
• Leaf of tree or flatfish (fluke)
• Trematode (suckers with hole in middle)
• Trematode : (trema : hole and eidos : appearance)

3. • I) Habitat classification :

4. 3) General characters
• 1)Morphology : adult worm , egg and larva
• i) Adult worm: unsegmented , Flattened dorsoventrally.
• A) size : 1mm to 6mm
• B) suckers: oral (mouth) and ventral suckers
• SEX NOT SEPERATE (EXCEPT SCHISTOSOMES)

5. AC , NO
ANUS
EC
MRC
MRC
FRC
FRC

6. SCHISTOSOMES MALE AND FEMALE

7. • Ii)Egg: oviparous(egg larva)
• All operculated except schistosome (nonoperculated –urine (spine)
•
enviroment

8. • III) Larvae : 5-larval (miracidium , sporocyst , redia, cercaria and
metacerceria)

9. 4)Lifecycle
• i) Definitive host :Mammals , humans or animals
• Ii) Intermediate host : freshwater molluscs or snail
• Second intermediate host : Fish or Crab (encystment)
• Schistosomes not need 2nd intermediate host

10. Rediae : 2nd generation
No rediae in schistosomes

11. Difference in life cycle of other trematodes and schistosomes
Metacerceria larvae (I.F in s.i.h -fish)
human by ingestion
lung, liver, intestine, bile duct
Adult worm
self fertilized (egg)
feses and sputum
miracidium larvae
Ingested by snail (1st i.h)
sporocyte
redia(1st & 2nd )
infective to man cercaria
metacercaria S.i.h (fish)
cerceria larvae (water)
Human Skin penetration
Enter venus circulation intestine &kidney
Adult worm
Cross fertilized
Egg in urine and stool
Miracisium in water
Snail (1st i.h)
Sporocyte (1st and 2nd )
Cercaria in water
Clonorchis
&
opisthorchis

12. 5)MODE OF INFECTION
• i) Ingestion (cercaeria):
• A) Vegetables: F.Hepatica , F.buski , W.watsoni
• B) fish: C.cinensis , H.heterophyes , M.yokogawai
• C) fish of crab or crayfish: P.westermani
• Ii) skin penetration: S.haematobium , S.mansoni , S.japonicum

13. 6) Blood Flukes
• A) Schistosomes :
• Sex seperate (dioecious)
• Schistossommiasis (water born disease)
• Africa , Latin America and Asia
• Schistosoma haematobium, S. japonicum, S. mansoni , S. mekongi and S.
intercalatum

14. • B) Order :strigeida
• C) Superfamily : schistosomatoidea
• D) Family : schistosomatidae
• E) Morphology: : adult worm , egg and larva
•

15. • Ii) eggs:
• 1) 70-180 micro m X 40-73 breadth
• 2) non operculated with spine
• S.haematobium :terminal
• S.mansoni: lateral
• S.japonicum: lateral rudimentary spine

16. • Iii) larva:miracidium , sporocyts (1st & 2nd ) &
cercaria (infective form )

19. Egg cell: not acidfast
Miracidium larvae in egg
:acid fast
Egg shell : acid
fast
Egg shell : acid
fast

20. f) Mechanism of Egg Expulsion
LAID
• EGG LAID enter into vesicle wall by spine
Small venus and pelvic
pelvic plexus ,
(mescentric portal
system ,pulmonary
arteries )
Release :
lytic
substance
passes
Lumen of urinary
bladder
Discharged :
urine
Skin –local
tissue
irritation
Egg –in feces

21. g) Life cycle of schistosomiasis

22. i)
Antigen from egg stimulate HMI Immune complex and serum sikness (c/d katyama
fever)
h) Pathogenesis and clinical features
Cercariae (skin penetration )
dermatitis , pruritis
Lung :cough with
fever

23. • a) urogenital disease : (s.hematobium)
• Symptomatic after 3 months
• EGG: pathogenic
• Egg urinary bladder (dysuria and hematuria)
D.Hypersensitivity
Urinary
bladder
Granuloma of
macrophage ,
lymphocyte
etc
Granuloma
join together
Granular
metaplasia
Heavy
infection
Elephanthasis
of scrotum
and penis
Important
pathogen in HIV
ii) Chronic schistosomiasis

24. • iii) Obstructive utropathies : (s.hematobium)
• Fibrosis
• iv) Bladder carcinoma: (s.hematobium) due to
metaplastic change
• i) predisposing factor :
• Diet containing nitroso compound (cheese , beans etc)
• Secondary bacterial infection
Obstruction
in lower
ureters
Hydroureter and
hydronephrosis

25. v)
vi) Hepatosplenic disese : (S.Mansoni & japonicum)
Granuloma formation and fibrosis in liver (symmers pipestem fibrosis)
Hypension , hepatomegaly , splenomegaly

26. • vii) cerebral schistosomiasis : s.japonicum
• 2-4% of cases
• Symptoms : jacksonian convulsion and grand male
fever

27. j) LABORATORY DIAGNOSIS
Urine microscopy
: urine and stool
(rarely) for
nonoporculated
egg
Collection time :
12pm to 3pm
Histopathology :
egg in bladder
mucosa biopsy
Ab detection in
serum
IgE & igG4 :
I) HAMA – FALCON
ASSAY SCREENING
TEST –ELISA
II) HAMA –EITB
(ENZYME LINKED
IMMUNOTRANSFER
BLOT
1) ANTIGEN
DETECTION : A)
Circulating
cathodic antige
(CCA) in serum
and urine by
ELISA
B) ELISA based
specific
monocolonal AB
against (M Ab –
SEA)

28. h) TREATMENT
• A) Praziquantel : 20 mg /kg/dose , two dose in
single day
• B) Metrifonate : inhibits acetylcholine
receptor on adult male worm . Multiple dose
for a week

29. 7)Liver flukes
• 1)Fasciola hepatica and F.gigantica
• 2)Colonorchis sinensis
• 3)Opisthorichis species
• 4)Dicrocoelium dendriticum

30. 1)Fasciola hepatica
• i) largest and most common in human(Greater liver fluke)
• Ii) Sheep (sheep liver fluke)
• Iii) G.D : Egypt
• Iv) host: Herbivorous animals and accidently man
• V)Habitat :liver and bile duct
• Vi) Disease: Fascioliasis(Liver Rot)

31. • Vii) Morphology :
• A) Adult:
• Leaf
• length 30mm long and 15mm
broad.
• Anteriorly (conical) and
posteriorly (round)
• Testes: Two
• Ovary: One

32. • B) Eggs:
• 140umx80um
• Oval
• Operculated
• immature embryo
• Bile stained

33. • C) larva:
• metacercaria (infective form)
• Miracidia
• Rediae
• Sporocyst

34. vii) Life cycle

36. viii) Pathogenesis, clinical and
complications
• 2 phages
• i) Acute or invasive phase: fever , right upper quandrant
pain , hepatomegaly and eosinophilia
• symptoms appear 2 weeks after the infection
• due to:
• Mechanical injury.
• Parasite toxin.
• Allergy to parasite ex-product
• Anemia and dyspepsia

37. • Ii) Chronic stage:
• maturing worm in the bile duct
• A) Ectopic fascioliasis
• In lung
• Subcutaneous tissue
• Rare central nervous system(rare)
Cholecystitis Cholelithiasis
,Jaundice , Liver fibrosis

38. • B) Halzoun (marrare sybdrome)
• Uncooked meat of sheep goat
• form of acute laryngopharyngitis.

40. 2)

41. • Eggs :
• flask shaped
• Operculum (prominent shoulder and
common shaped knob)

42. • Larvae :
• metacercaria (infective form)
• Miracidia
• Rediae
• Sporocyst

43. • Mode of transmission
• Eating of frozen, dried or pickled fish (metacercariae).

44. Life cycle

46. Pathogenesis
• cholangitis.
• Cholangiocarcinoma.
• Calculus formation.
• Few cases :
• Biliary cirrhosis.
• Portalhypertension.

47. • Clinical Picture :
• Fever
• epigastric pain
• diarrhea
• tender hepatomegaly
• biliary colic
• obstructive jaundice.

48. Laboratory diagnosis

49. INTESTINAL FLUKES
PROPERTIES F.BUSKI
Habitat Jejunum and duodenum
(man & pig)
Epidermiology U.P , bihar , west bengal
Assam and maharastra
Adult worm 2-7.5 cm
Cephalic cone Absent
Suckers Oral and ventral
egg Biled stained
Larvae Metacerceria (I.F)
Host D.H-PIG /MAN , 2 I.H-
SNAIL , PLANT

50. PATHOGRNESIS
MALABSORPTION WITH YELLOWISH GREEN COLOUR STOOL

51. LAB DIAGNOSIS
• STOOL : oporculated egg

52. Lung fluke (paragonium
westermani/oriental lung fluke)
Properties paragonium westermani
Epidermiology Manipur , north east states of india
Habitat Paranchyma of lung
Adult worm Reddish brown , broad anterior end ,
Excretory bladder : divided body into 2
part
egg Oval , golden brown, 80-120 micro m X 45-
65 micro m
larvae Metacerceria (I.F) ,
Host D.H- (Man , dog , cat) , 2 I.H – (Snail , crab)

55. Pathogenesis
Intestinal complication Pulmonary paragonimiasis Extrapulmonary
paragonimiasis
Abdominal tederness Initially : eosinophilic
granulomatous inflamation
Cerebral paragonimiasis :
fever , headeche vomiting
and motor weakness
Nausea Cyst surrounding worm Cutaneous paragonimiasis :
subcutaneous nodule
Vomiting Cyst (blood & fluid )
Cyst break into bronchioles
Expectoration of brownish
blood sputum with offensive
fishy order
Bronchitis, bronchiectasis
,pneumonia and lung abscess

56. Laboratory diagnosis
1) Sputum
microscopy : early
morning sample mount
with saline (operculated
egg)
2) Formal ether
method
3) Stool
microscope in
children (sputum difficult
to collect)
Serology :
1) Ab detection :
a) Rapid test : dot immunogold
filtration assay , ELISA (IgG
or IgE)
2) Antigen detection : dot
ELISA (ACTIVE INFECTION)
MRI , CT scan (cyst
in CNS)