Fasciola Hepatica – Liver Fluke , Resides In The Bile Ducts, Chronic Renal Failure

Fasciola hepatica
(the sheep liver fluke)

The common name of this parasite, the “sheep liver fluke,” is somewhat misleading since this parasite is found in animals other than sheep (including cattle and humans), and the parasite resides in the bile ducts inside the liver rather than the liver itself.  This species is a common parasite of sheep and cattle and, therefore, relatively easy to obtain.  Thus, in introductory biology or zoology courses, it is often used as “THE” example of a digenetic trematode.  This species has been studied extensively by parasitologists, and probably more is known about this species of digenetic trematode than any other.


The adult parasites reside in the intrahepatic bile ducts, produce eggs, and the eggs are passed in the host’s feces.  After passing through the first intermediate host (a snail), cercariae encyst on vegetation.  The definitive host is infected when it eats the contaminated vegetation.  The metacercaria excysts in the definitive host’s small intestine, and the immature worm penetrates the small intestine and migrates through the abdominal cavity to the host’s liver.  The juvenile worm penetrates and migrates through the host’s liver and finally ends up in the bile ducts ( view a diagram of the life-cycle).  The migration of the worms through the host’s liver, and the presence of the worms in the bile ducts, are responsible for the pathology associated with fascioliasis.

Fasciola hepatica is found in parts of the United States ( view distribution), as well as in Great Britian, Ireland, Europe, the Middle East, the Far East, Africa, and Australia.  Fascioliasis in sheep and cattle results in animals that show low productivity (low weight gain, low milk production, etc.).  Also, in many countries, livers from animals infected with F. hepatica are condemned as unsuitable for human consumption.  This not only results in a significant economic loss to ranchers and farmers, but it also results in the loss of an important source of protein.  The infection can be diagnosed by finding eggs in the feces of animals, but the eggs are difficult to differentiate from closely related species such as Fasciolopsis buski.  Several immunological methods for diagnosis are available.
http://www.biosci.ohio-state.edu/~parasite/fasciola.html

KIDNEY PATHOLOGY IN CATTLE NATURALLY INFECTED BY FASCIOLA HEPATICA
Marques, S.T.1, Scroferneker, M.L.2, Edelweiss, M.I.3

Abstract

Kidney specimens of 51 animals, 27 with fascioliasis and 24 uninfected animals (controls), were examined by light microscopy, direct immunofluorescence (DIF), indirect immunofluorescence (IIF), and immunohistochemistry. In animals infected by Fasciola hepatica, the sections stained with hematoxylin and eosin (HE), periodic acid-Schiff (PAS) and Massons trichrome revealed mesangioproliferative glomerulonephritis (33.3%) and membranoproliferative glomerulonephritis (44.5%). On DIF, 100% of the animals with fascioliasis had granular and pseudolinear IgG deposits; while 70.4% (19 animals) had this lesion on IIF. Furthermore, Fasciola hepatica antigen was found in 20 infected animals by immunohistochemistry,. Our conclusion is that there is a glomerulopathy associated with fascioliasis, and that cattle can serve as an experimental model to detect immune-mediated renal injury caused by natural Fasciola hepatica infection.

Key words: fascioliasis, parasitic diseases, chronic renal failure, glomerulonephritis.

Introduction

Liver fluke disease or fascioliasis is an important parasitic disease that affects cattle, sheep, goats, buffaloes, wild animals, and man worldwide. This disease causes significant economic losses, great expenses with antihelmintics, in addition to liver condemnation, production loss due to mortality, lower production of meat, milk and wool; reduced weight gain, and impaired fertility, also impeding the selection of animals (1-2). Renal involvement in parasitic diseases has several clinical manifestations, including hematuria, mild proteinuria, nephrotic syndrome, and chronic renal failure. Glomerular changes range from mild and transient mesangial proliferation to well-defined glomerulonephritis. In the acute phase of some parasitic diseases such as hydatid disease, trichinosis and leishmaniasis, mesangioproliferative glomerulonephritis is observed, but tends to disappear when the parasitic infection is under control. Deposits of IgG, IgM and C3 suggestive of circulating immune complexes can be observed in glomeruli (3-4). Glomerulonephritis in chronic parasitic diseases was reported in leishmaniasis, hydatid disease, schistosomiasis, malaria and dirofilariasis (5-10). The renal injuries caused by parasitic diseases involve nonspecific mechanisms, parasitic migration, and immunological mechanisms. The aim of our study was to assess glomerulopathy in cattle naturally infected by Fasciola hepatica in the State of Rio Grande do Sul, southern Brazil.

http://www.isrvma.org/article/60_1_3.htm

Fascioliasis, Man
Fascioliasis describes an infection of the bile ducts with Fasciola hepatica, the liver fluke of sheep, cattle, and man. After the ingestion of the metacercaria encysted on water plants (water cress salad), the larvae wander through the wall of the gut, into the liver parenchyma, and into the bile ducts. The migration tracts are accompanied by an intense inflammatory reaction with prominent eosinophils and Charcot-Leyden crystals, resolving ultimately by fibrosis ( Pathology/Fig. 3A,B, Pathology/Fig. 21A,C). The liver may be enlarged and show abnormal function. Blood leukocytosis with eosinophilia, and fever are prominent. After long-standing infection with flukes, bile duct hyperplasia , pericholangitis, periportal fibrosis, and obstruction of the bile duct may develop. F. hepatica eggs are shed in the stools.

http://parasitology.informatik.uni-wuerzburg.de/login/frame.php?splink=/login/n/h/0500.html

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