Pathology of liver fluke Amphimerus spp. infection in ducks (Anas platyrhynchos) in Haor areas of Bangladesh Rahman M.H.2,*, Hossain M.M.2, Nooruzzaman M.2, Hassan M.1,2, Alim M.A.1,2, Farjana Thahsin1,2, Hossain M.I.2 2Department of Pathology, Bangladesh Agricultural University, Mymensingh, Bangladesh 1Department of Parasitology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh *Corresponding author: rahmanmdhabib@gmail.com
Abstract Amphimerus spp. is a liver fluke which recently has been shown to have a high prevalence of infection in open air Jinding duck herd in the Haor areas of north-east of Bangladesh. Since it is unknown which animals can act as a reservoir and/or definitive hosts for Amphimerus spp. in this endemic area, a study was carried out to determine the effects in the duck. In November 2017, a total of 69 ducklings of age 75 days were subjected to details of pathological examination for the Amphimerus infection. The results have shown that the liver fluke (Amphimerus anatis) had destroyed 80–90% of the functional tissues of the liver parenchyma of ducks where it inflicted severe damage to all hepatic structures with the consequent development of fibrosis and cirrhosis. Acute extrahepatic obstruction was characterized by a proliferative reaction by the biliary epithelium of the bile ducts. Biliary hyperplasia of bile ductules was often prominent. In severe cases, bridging fibrosis connecting portal tracts have been found to be developed. Top Keywords Amphimerus anatis, Duck, Liver cirrhosis, Zoonosis. Top |
ACKNOWLEDGEMENTS The authors are grateful to the Director, BAURES for providing financial support and the Dean, Faculty of Veterinary Science, Bangladesh Agricultural University and Head, Department of Pathology for facilities to carry out this work. |
Top Figures | Fig. 1.: Amphimerus anatis exytacted from the liver of duck. Note: Prominent oral sucker with short oesophagus
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| | Fig. 2.: Eggs of Amphimerus spp. observed in stools from bile sample of duck died of Amphimeriasis
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| | Fig. 3.: Liver from ducks suffered from Amhimeriasis. Note the nodular pattern and the areas as pale tan areas
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| | Fig. 4.: Cross-sectional view of the liver from a duck infected by Amphimeru sanatum. Note the nodular pattern and the areas of greenish discoloration. These green nodules (arrows) are actually the viable hepatocytes that are stained green because of bile stasis. The pale areas are the areas of fibrosis
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| | Fig. 5.: A low-power photomicrograph of this liver to highlight the fibrous tissue (arrows). Also note the nodular pattern. Ova are discharged by the encysted parasites located within the hepatic parenchyma. These structures are surrounded by a focus with light brown pigment (arrows). H&E × 100
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| | Fig. 6.: Duck liver section showing Amphimeru sanatum encysted within the hepatic parenchyma. The parasite, shown in cross sections, is separated from the hepatic parenchyma by a thick wall of fibrous connective tissue (arrow). Note atrophic hepatocytes and the liver lobes appear to be deformed
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| | Fig. 7.: Liver section of duck died of Amphimeriasis. Note acute proliferative reaction by the biliary epithelium of the portal areas. Portal areas are enlarged by deposition of fibrosis, and there is a biliary hyperplasia characterized by proliferation of bile ductules (arrows). H&E ×100
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| | Fig. 8.: Liver showing mature trematodes engorged with ova. Note pressure from the cyst has obliterated preexisting hepatic parenchyma
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| | Fig. 9.: Liver section from an Amphimariasis affected duckling showing cirrhosis. Note the nodules, the fibrosis, the green coloration and the small size of this cirrhotic liver. The bands of fibrous tissue are seen to form “bridges” between triad areas (arrows); this is called “bridging fibrosis.” Also note the fibrous tissue (arrows) and how the hepatocytes are separated into nodules by this fibrous tissue. H&E ×100
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| | Fig. 10.: Duodenum from duck died of Amphimeriasis. Note mucosa showing early necrosis with hyperemia extending all the way from mucosa to submucosal and muscular wall. The muscularis, however, are still intact. Necrosis of the mucosa of the duodenum shows hemorrhage with acute inflammation.H&E × 450
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| | Fig. 11.: Section of renal blood vessel from duck died of Amphimeriasis. Note focally, the necrosis extends through entire aortic wall and there is continuity oflumen to beyond tunica adventitia (focal rupture). The tunica adventitia is thickened by proliferation of mesothelial cells, granulation tissue. Homogenous glassy pink material is seen outside the renal vessel wall. H&E ×100.
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