trematodes helminthes. in general: they are flat worms provided with suckers as organs of...
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TREMATODES
Helminthes
In general:
They are flat worms
Provided with suckers as organs of attachment
Usually as leaf shape
Commonly known as Flukes
No body cavity
Male and Female systems are together with
Schistosomes as an exception.
1- Liver Fluke (Fasciola):
Adult: with shoulders
Egg: oval in shape and it’s operculated, it’s immature.
Hosts: Man : definitive host, Snail: first intermediate
host, Vegetations: second intermediate host.
Habitat: bile duct.
Infective stage: Encysted Metacercaria.
Complication: bile duct obstruction (Jaundice).
Diagnosis:
High eosinophilia
Stool examination: egg in stool
Serology
CT scan or Ultrasound.
We have to differentiate between true fascioliasis and false fascioliasis
The two conditions release eggs of Fasciola. False Fasciola: results from eating infected liver
of animals as Fasciola may affect sheep, buffalo. In this condition, the patient release eggs in the stool, but without infection with fasciola.
To differentiate between true and false Fasciola: we forbid the patient from eating animal liver for three days, then we repeat stool examination. If eggs disappear, it is false fascioliasis, but if eggs still present in the stool, it is true fascioliasis.
2- Fasiolopsis buski (Intestinal Fluke):
Adult without shoulders.
Habitat: small intestine.
Egg: oval in shape with small operculum, immature.
Infective stage: Encysted Metacercaria
Hosts: Man: Definitive host, Snail: first Intermediate
host, Chest nut: second intermediate host.
Complication: may lead to intestinal obstruction in
the case of presence of large number of worms.
Diagnosis:
Stool Examination: egg in stool
Serology
3- Paragonimus (Lung Fluke): Adult: oval in shape with 2 suckers. Egg: small, oval, operculated,
immature. Infective stage: Encysted
Metacercaria Hosts: Man: Definitive host, Snail:
first intermediate host, Crap fish: second intermediate host.
Can lead to Pneumonia and lung abscesses.
Diagnosis:
Sputum Examination.
Stool examination in some cases (specially in children) when swallowed.
4- Schistosoma (Blood Fluke): Have 3 species can be easily differentiated
by their egg shape. Adult: differs from other trematodes in being
separate sex. Eggs for all species are mature. A- Haematobium: Habitat: blood vessels around the UB. Egg: Yellowish, mature with terminal spine. Diagnosed by Urine examination.
B- Mansoni:
Habitat: Inferior vein of large intestine
Egg: large, yellowish with lateral spine
Diagnosed by : stool examination.
C- Japonicum:
Habitat: Superior veins in small intestine
Egg: small, rounded with small lateral spine.
Diagnosed by: stool examination.
Mansoni
Japonicum
S. Japonicum is the most dangerous species:
It is serious. Starts by katayama fever which is manifested by fever, hepatosplenomegaly and lymphadenopathy.
Severe complications are in the form of cerebral and spinal cord affection leading to epilepsy and hemiplegia.