The histopathology of Fasciola hepatica infections in sheep

Experimental infections of lambs with Fasciola hepatica are described. The growth rate of the parasite, time of entry to the bile ducts, and time of patency are recorded and a preferential migration of the parasite in the liver parenchyma noted. The gross and histological lesions produced in the liver from 1 to 40 weeks after infection are described and compared with previous observations in cattle.The parenchymal migration of the parasite is shown to consist of two phases, a free migrating phase up to the 6th week, and a localized phase after the 6th week prior to entry into the bile ducts. Hepatic cell regeneration is observed and hepatic fibrosis is minimal. The localized phase of migration is associated with a unique peripheral palisade of giant cells in the fluke tracts and with the formation of pseudofollicular aggregation of lymphocytes. The presence of flukes in the bile ducts produces fibrosis of the duct walls. The walls, however, remain pliable and expanded to accommodate the parasites and calcification was never observed.

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A Partially Protective Vaccine for Fasciola hepatica Induced Degeneration of Adult Flukes Associated to a Severe Granulomatous Reaction in Sheep

Animals ◽

10.3390/ani11102869 ◽

2021 ◽

Vol 11 (10) ◽

pp. 2869

Author(s):

Verónica Molina-Hernández ◽

María T. Ruiz-Campillo ◽

Francisco J. Martínez-Moreno ◽

Leandro Buffoni ◽

Álvaro Martínez-Moreno ◽

...

Keyword(s):

Bile Ducts ◽

Plasma Cells ◽

Fasciola Hepatica ◽

Vaccine Trial ◽

Granulomatous Inflammation ◽

Giant Cells ◽

Control Group ◽

Infected Control Group ◽

Hepatic Lesions ◽

Host Parasite

Fasciolosis is an important economic disease of livestock. There is a global interest in the development of protective vaccines since current anthelmintic therapy is no longer sustainable. A better knowledge of the host-parasite interaction is needed for the design of effective vaccines. The present study evaluates the microscopical hepatic lesions in sheep immunized with a partially protective vaccine (VAC1), a non-protective vaccine (VAC2), and an infected control group (IC). The nature of granulomatous inflammation associated with degeneration of adult flukes found in the VAC1 group was characterized by immunohistochemistry. Hepatic lesions (fibrous perihepatitis, chronic tracts, bile duct hyperplasia, infiltration of eosinophils and lymphocytes and plasma cells) were significantly less severe in the VAC1 group than in the IC group. Dead adult flukes within bile ducts were observed only in the VAC1 group and were surrounded by a severe granulomatous inflammation composed by macrophages and multinucleate giant cells with a high expression of lysozyme, CD163 and S100 markers, and a low expression of CD68. Numerous CD3+ T lymphocytes and scarce infiltrate of FoxP3+ Treg and CD208+ dendritic cells were present. This is the first report describing degenerated flukes associated to a severe granulomatous inflammation in bile ducts in a F. hepatica vaccine trial.

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Radiological Imaging Features of Fasciola hepatica Infection – A Pictorial Review

Journal of Clinical Imaging Science ◽

10.4103/2156-7514.92372 ◽

2012 ◽

Vol 2 ◽

pp. 2 ◽

Cited By ~ 35

Author(s):

Abdurrahim Dusak ◽

Mehmet R. Onur ◽

Mutalip Cicek ◽

Ugur Firat ◽

Tianbo Ren ◽

...

Keyword(s):

Fasciola Hepatica ◽

Multimodality Imaging ◽

Liver Parenchyma ◽

Imaging Features ◽

Pictorial Review ◽

Magnetic Resonance Imaging Mri ◽

Us Findings ◽

Two Phases ◽

Water Plants ◽

Stool Analysis

Fascioliasis refers to a zoonosis caused by Fasciola hepatica, a trematode infecting herbivores, but also occurs in humans who ingest the metacercaria found in fresh water plants. Infection in humans is common in developing countries and is also not uncommon in Europe. Diagnosis of this infection is difficult, as the history and symptoms are nonspecific and stool analysis for eggs is negative until the disease is in an advanced state by when the parasite has reached the biliary system. The clinical course consists of two phases; first a hepatic parenchymal phase in which immature larvae invade the liver parenchyma, followed by a ductal phase characterized by the excretion of larvae into the bile ducts. Parenchymal Phase: Ultrasonography (US) findings are nonspecific in this early phase. Computerized tomography (CT) may demonstrate subcapsular low attenuation regions in the liver. Magnetic Resonance imaging (MRI) can also be utilized to establish liver parenchymal involvement, and is better than CT in characterizing hemorrhagic lesions, as well as identifying more lesions relative to CT. Ductal Phase: US examination is most useful at this stage, with its ability to demonstrate the live movement of the worms within the dilated ducts. A CT demonstrates dilated central biliary ducts with periportal tracking, whereas, mild ductal dilatation is poorly appreciated under MRI. Therefore, familiarity with the multimodality imaging features of fascioliasis, in combination with an available confirmatory enzyme-linked immunoassay, would be most helpful for early diagnosis.

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Experimental Infections of Cattle with Fasciola hepatica: High level single infections in calves

Journal of Helminthology ◽

10.1017/s0022149x0002160x ◽

1967 ◽

Vol 41 (2-3) ◽

pp. 217-222 ◽

Cited By ~ 9

Author(s):

J. G. Ross

Keyword(s):

Bile Ducts ◽

Fasciola Hepatica ◽

Clinical Disease ◽

Experimental Infections ◽

Lower Infection ◽

High Level

Single experimental infections of 8 to 12 week old calves with 200 to 15,000 metacercariae are described. It is shown that as the level of metacercariae infection rises the numbers of fluke reaching and persisting in the bile ducts fall. In the higher infections the majority of the flukes are trapped and eliminated in the parenchyma and clinical disease does not develop. In lower infection levels the majority of the flukes reach the bile ducts and clinical disease develops.

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On the Ultrastructure of Epithelial Cells in Bile Ducts of Cattle Chronically Infected with Fasciola Hepatica

Acta Veterinaria Scandinavica ◽

10.1186/bf03547441 ◽

1973 ◽

Vol 14 (2) ◽

pp. 233-244

Author(s):

Timo Rahko

Keyword(s):

Epithelial Cells ◽

Bile Ducts ◽

Fasciola Hepatica

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Chronic Wasting Due to Liver and Rumen Flukes in Sheep

Animals ◽

10.3390/ani11020549 ◽

2021 ◽

Vol 11 (2) ◽

pp. 549

Author(s):

Alexandra Kahl ◽

Georg von Samson-Himmelstjerna ◽

Jürgen Krücken ◽

Martin Ganter

Keyword(s):

Fasciola Hepatica ◽

Clinical Symptoms ◽

Current Knowledge ◽

Infection Intensity ◽

Liver Parenchyma ◽

Trematode Species ◽

Helminth Infections ◽

Juvenile Worm ◽

Juvenile Stages ◽

Common Liver Fluke

Grazing sheep and goats are constantly exposed to helminth infections in many parts of the world, including several trematode species that causes a range of clinical diseases. The clinical picture of flukes is dependent upon the organs in which they develop and the tissues they damage within the respective organs. Accordingly, infections with the common liver fluke Fasciola hepatica, which, as juvenile worm migrates through the liver parenchyma for several weeks, may be associated with hepatic disorders such as impairment of carbohydrate, protein and fat metabolism, followed by chronic wasting. In contrast, the lancet fluke Dicrocoelium dendriticum, which does not exhibit tissue migration and thus does not lead to major tissue damage and bleeding, also does not lead to significant clinical symptoms. Rumen flukes such as Cotylophoron daubneyi cause catarrhal inflammation during their migration through the intestinal and abomasal epithelium during its juvenile stages. Depending on the infection intensity this may result in a range of clinical symptoms including diarrhoea, inappetence or emaciation. In this review, we aim to provide an update on the current knowledge on flukes particularly concerning the clinical relevance of the most important fluke species in sheep.

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Growth, development and allometry of Philophthalmus nocturnus in the eyes of domestic chicks

Journal of Helminthology ◽

10.1017/s0022149x00012669 ◽

1992 ◽

Vol 66 (2) ◽

pp. 100-107 ◽

Cited By ~ 5

Author(s):

V. G. M. Swarnakumari ◽

R. Madhavi

Keyword(s):

Growth Rate ◽

Developmental Stages ◽

Adult Stage ◽

The Body ◽

Lag Phase ◽

Allometric Growth ◽

Body Width ◽

Rapid Phase ◽

Growth Development ◽

Two Phases

ABSTRACTFifty day-old chicks were each infected with 10 excysted metaccreariae of Philophthalimus nocturnus Looss. 1907 around each orbit and growth, development and allometry were studied. The growth rate showed two phases over a period of 35 days, a limited lag phase lasting two days post-infection in which flukes did not exceed 440 μm in length, and a rapid phase during which growth was rapid and flukes reached a size of 3·008–3·504 mm on day 35. Five developmental stages were noticed during the course of development of the metacercaria to the egg-producing adult stage. Eggs appeared in the uterus on day 14 and oculate miracidia on day 25. The hindhody, testes and ovary showed positive allometric growth, the pharnyx less so, whereas negative allometric growth was shown by the forebody. Body width, oral sucker and ventral sucker were close to isometry, growing at the same rate as the body length.

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Characterization and Frequency of Histological Changes in Bovine Livers from Slaughterhouses in Brazil kept on Brachiaria spp.

Acta Scientiae Veterinariae ◽

10.22456/1679-9216.79385 ◽

2017 ◽

Vol 45 (1) ◽

pp. 9

Author(s):

Rebekah Rank Araújo ◽

Rayane Chitolina Pupin ◽

Renata Cunha Madureira ◽

Luiz Gustavo de Morais ◽

Lucas De Souza Quevedo ◽

...

Keyword(s):

Bile Ducts ◽

Rio Grande ◽

Liver Parenchyma ◽

Rio Grande Do Sul ◽

Histopathological Changes ◽

Steroidal Saponins ◽

Histological Changes ◽

Mato Grosso ◽

Native Pastures ◽

Foamy Macrophages

Background: Brachiaria spp. is the main pasture for ruminant productions in Brazil, but the limiting factor for its use is the toxicity due to the presence of steroidal saponins. Chronic ingestion of Brachiaria spp. by cattle may cause liver changes such as fibrosis, bile duct proliferation and clusters of foamy macrophages in the hepatic parenchyma. The main objective of the present study was to evaluate the most frequent histological changes and their frequencies in livers collected in abattoirs in Brazil from beef cattle raised exclusively on Brachiaria spp. and compare them with those observed in animals kept in Andropogon spp. grass and native pastures in Rio Grande do Sul.Materials, Methods & Results: Liver samples without macroscopic changes were collected in abattoirs from 561 healthy Nelore and Nelore crossbred cattle raised in Brachiaria spp. pastures from Mato Grosso (MT), Mato Grosso do Sul (MS), Minas Gerais (MG) and Pará (PA) States. Liver samples from 84 Angus cattle (Bos taurus) kept on native pastures in Rio Grande do Sul (RS) and from 60 Nelore and Nelore crossbreed cattle raised in Andropogon spp. pastures in Tocantins State (TO) were collected as control. Semi-quantitative analysis of the histopathological changes were proceeded: (-) = no change; (+) = slight or discreet change; (++) = moderate change and (+++) = marked change. The main histopathological changes evaluted in the liver samples were the presence of foamy macrophages and its location, parenchymal fibrosis and its location, proliferation of bile ducts, periportal mononuclear infiltrate, presence of crystals in macrophages and within the bile ducts. Foamy macrophages clusters in the liver parenchyma were the most frequent histological changes exclusively observed in samples of animals kept in Brachiaria spp. and it was more frequent in cattle from MS State (P < 0.0001). The periportal hepatic fibrosis was another relevant finding in cattle kept in Brachiaria spp. and was also more frequent in MS animals (P ≤ 0.0001), and was not present in control groups. Proliferation of the bile ducts rate was similar between animals raised in Brachiaria spp. (P > 0.05), though it was higher in cattle kept on native pasture in RS (P < 0.0001). The mononuclear periportal inflammatory infiltrate was more frequent in MS and MG samples than in MT and PA (P < 0.0002).Discussion: The most significant histopathological changes observed in liver samples of cattle from the states of MT, MS, PA and MG kept in Brachiaria spp. pastures from the birth to slaughter, was the presence of foamy macrophages in quantities and variables distribution showing the strengthen association between clusters of foamy macrophages in the liver parenchyma and grazing on this grass. These macrophages could be found in healthy animals kept in Brachiaria spp. pastures and in intoxicated animals. This change was considered frequent and characteristic in animals kept in pastures containing steroidal lithogenic saponins in its composition, and it was frequently observed in ruminants that growed in Brachiaria spp. pastures. Beef cattle kept in Andropogon spp. grass pastures in the state of Tocantins and native pastures in Rio Grande do Sul did not showed foamy macrophages in liver samples. On the other hand, in susceptible sheep kept in Andropogon spp. grass pastures that contains low amount of lithogenic steroidal saponins, are insufficient to induce toxicity and morphological changes in the liver, including aggregates of foamy macrophages.

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