24 Fasciola
24 Fasciola
24 Fasciola
Fasciola hepatica
The common names are the sheep liver fluke and the common liver fluke.
The anterior end bearing the oral sucker forms a conical projection.
The acetabulum is situated in a line with the two shoulders formed by the
broadening of the conical projection posteriorly.
Contd.
Life span of the adult worm in sheep is 5 years and in man 9 to 13 years.
During migration of the young worms and their localisation in the biliary passages,
they cause extensive damage to the liver and in heavy infections, may lead to portal
cirrhosis.
While in the biliary passages, they may interfere with normal flow of bile , causing
obstructive jaundice.
Contd.
The mature worms cause marked pathological changes in the biliary tract
by mechanical irritation as well as by their toxic secretion.
They produce cystic dilatation of the bile ducts, the walls of which become
greatly thickened by the development of fibrous tissue.
In the more chronic phases of the disease, the patient generally has few to
no symptoms once the flukes have lodged in the biliary passages.
Larvae may be found in ectopic foci after penetrating the peritoneal cavity.
Contd.
Once the worms have established themselves in the bile ducts and matured.
In areas of endemicity where uncooked goat and sheep livers may be eaten,
such as Lebanon, adult worms may attach to the pharyngeal mucosa,
causing suffocation(halzoan syndrome).
It has a shorter cephalic cone, a larger ventral sucker and a more anterior position of
the testes.
The eggs of F.gigantica are larger (180m x 80m) than those of F.hepatica (140m
x 80m).
The prepatent period between infection and the presence of adult worms in
the bile ducts is 9 to 12 weeks.
Although these eggs are larger than those of F.hepatica or F.buski, they are
very similar in shape.
Treatment-Same as F.hepatica.