liver fluke
Fasciola hepatica
sheep liver fluke
Fasciola hepatica
• Common name: The sheep liver fluke
• Habitat: Bile duct of liver.
• Route of infection: Man eat aquatic plants with
encysted metacercariae.
• Definitive host: Usual host sheep, infects liver of
various mammals, including humans.
• Intermediate host: Fresh water snails.
• Infective stage: Encysted metacercariae on
vegetations.
• Diagnostic stage: Eggs in stool specimen.
• Disease: Fascioliasis.
Fasciola hepatica adult
Morphological characteristics
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2-3 cm.
Has conical projection
Oral and ventral sucker.
Pharynx.
Branched caecum.
Coiled uterus
Genital formula : O ( ovary)
T ( Testis)
T ( Testis)
Fasciola hepatica Eggs
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Unembyonated.
Thin egg shell.
operculated.
130-150 X 63-90 um.
Diagnostic stage
egg capsule with emerging miracidium of
Fasciola hepatica
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Life cycle
• The parasite browses on liver tissue for a period of up to 5-6
weeks and eventually finds its way to the bile duct where it
matures into an adult and begins to produce eggs.
• Up to 25,000 eggs per day per fluke can be produced, and in a
light infection, up to 500,000 eggs per day can be deposited
onto pasture by a single sheep.
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Pathology and clinical symptoms.
• Most of the damage results from worms are migrating
through the liver parenchyma feeding on liver cells and
blood
• Worms in the bile ducts cause inflammation and edem
• The triad of fever, hepatomegaly, and eosinophilia.
• Symptoms and signs are associated with biliary obstruction
• Acute epigastric pain, and jaundice are common.
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diagnosis
Laboratory diagnosis:
finding large operculated eggs in the feces.
Intestinal fluke
Fasciolopsis buski
Fasciolopsis buski
• Common name: The large intestinal fluke
• Habitat: Lumen of small intestine.
• Route of infection: Man eat uncooked plants with encysted
metacercariae.
• Definitive host: Mainly human, other hosts; pigs and dogs.
• Intermediate host: Fresh water snails.
• Infective stage: Encysted metacercariae on vegetations.
• Diagnostic stage: Eggs in stool specimen.
• Disease: Fasciolopiasis.
Fasciolopsis buski adult
Morphological characteristics
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2-7x 0.5-2 cm.
Oral and ventral sucker.
Esophagus .
Unbranched caecum.
Coiled uterus.
Branched ovary.
Branched Testes.
Genital formula : O ( ovary)
T ( Testis)
T ( Testis)
This photo is to compare the sizes of Fasciolopsis buski
(left) and Fasciola hepatica (right)
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Fasciolopsis buski Eggs
• Unembyonated.
• Thin egg shell.
• Inconspicuous.
operculum.
• 130-150 X 63-90 um
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Clinical features
• Most infections are light and asymptomatic. In
heavier infections, symptoms include diarrhea,
abdominal pain, fever, ascites, and intestinal
obstruction.
Laboratory diagnosis:
operculated eggs and some times the adults are
found in the feces.
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Lung Fluke
Paragonimus westermani
Paragonimus westermani
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Common name: The Lung Fluke.
Habitat: Encapsulated in Lungs.
Definitive host: Human, also other mammals.
First intermediate host: Water snail.
Second intermediate host: Crustaceans,Crabs.
Infective stage: Encysted metacercariae.
Diagnostic stage: Eggs in sputum or feces.
Disease: Paragonimiasis.
morphology
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7 – 12 x 4 – 6 mm.
Oral & Ventral Suckers
Unbranched caecum.
Pharynx.
Coiled Uterus ( black color)
Genital formula: O
T T
Paragonimus westermani
Paragonimus westermani Eggs
• 80-120 x 50-60 um
• Large, thick, dark shell.
• Prominent operculum at
the broad end.
• Thick posterior end.
• Unembryonated.
Life Stages
Egg  Miracidio
RediaI Redia II
Cercarias Metacercarias
Paragonimus westwermani
• Pathology:
Adults in lungs stimulate inflammatory response
resulting in granulomas. Movement of worms to
heart or brain causes death.
• Symptoms:
 Chronic cough , difficulties breathing , sputum
with blood.
 When moves to brain, can cause blindness,
paralysis , disequilibrium , epilepsy.
DIAGNOSIS
• based on detection of characteristic eggs in sputum, or
stool,
• serology helpful; standard test is complement fixation
(CF) – has advantage to detect rapid decline in antibody
levels