<abstract xmlns="http://www.w3.org/1999/xhtml">

<sec id="j_jvetres-2019-0073_s_005">
<h3>Introduction</h3>
<p>The study of histopathological changes caused by influenza A (H5N8) viral infection in bird species is essential for the understanding of their role in the spread of this highly infectious virus. However, there are few such studies under natural conditions in minor gallinaceous species. This article describes the pathomorphological findings in Colchis pheasants infected naturally with H5N8 during an epizootic outbreak in Bulgaria.</p>
</sec>
<sec id="j_jvetres-2019-0073_s_006">
<h3>Material and Methods</h3>
<p>Samples of internal organs of 10 carcasses were collected for histopathological and immunohistochemical evaluation, virus isolation and identification, and nucleic acid detection.</p></sec>
<sec id="j_jvetres-2019-0073_s_007">
<h3>Results</h3>
<p>Consistent macroscopic findings were lesions affecting the intestine, heart, lung, and pancreas. Congestion and mononuclear infiltrate were common findings in the small intestine, as were necrosis and lymphoid clusters in the lamina propria of the caeca. Congestion with small focal necrosis and gliosis with multifocal nonpurulent encephalitis were observed in the brain. Myocardial interstitial oedema and degenerative necrobiotic processes were also detected. Immunohistological analysis confirmed systemic infection and revealed influenza virus nucleoprotein in all analysed organs.</p></sec>
<sec id="j_jvetres-2019-0073_s_008">
<h3>Conclusion</h3>
<p>Variable necrosis was observed in the brain, liver, trachea, heart, small intestine, and caeca. Viral antigen was commonly found in the brain, heart, lung and trachea. Contact with migrating waterfowls was suspected as a reason for the outbreak.</p></sec>
</abstract>

Introduction
The study of histopathological changes caused by influenza A (H5N8) viral infection in bird species is essential for the understanding of their role in the spread of this highly infectious virus. However, there are few such studies under natural conditions in minor gallinaceous species. This article describes the pathomorphological findings in Colchis pheasants infected naturally with H5N8 during an epizootic outbreak in Bulgaria.


Material and Methods
Samples of internal organs of 10 carcasses were collected for histopathological and immunohistochemical evaluation, virus isolation and identification, and nucleic acid detection.

Results
Consistent macroscopic findings were lesions affecting the intestine, heart, lung, and pancreas. Congestion and mononuclear infiltrate were common findings in the small intestine, as were necrosis and lymphoid clusters in the lamina propria of the caeca. Congestion with small focal necrosis and gliosis with multifocal nonpurulent encephalitis were observed in the brain. Myocardial interstitial oedema and degenerative necrobiotic processes were also detected. Immunohistological analysis confirmed systemic infection and revealed influenza virus nucleoprotein in all analysed organs.

Conclusion
Variable necrosis was observed in the brain, liver, trachea, heart, small intestine, and caeca. Viral antigen was commonly found in the brain, heart, lung and trachea. Contact with migrating waterfowls was suspected as a reason for the outbreak.

Pathological changes in natural infection of pheasants with highly pathogenic avian influenza A (H5N8) in Bulgaria

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Introduction
The study of histopathological changes caused by influenza A (H5N8) viral infection in bird species is essential for the understanding of their...

Pathological changes in natural infection of pheasants with highly pathogenic avian influenza A (H5N8) in Bulgaria

Published Online: Dec 19, 2019

Page range: 497 - 502

Received: Jun 17, 2019

Accepted: Nov 22, 2019

DOI: https://doi.org/10.2478/jvetres-2019-0073

Keywords
pheasants, avian influenza A virus, histopathology, immunohistochemistry, Bulgaria

© 2019 G.M. Stoimenov et al. published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

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Pathological changes in natural infection of pheasants with highly pathogenic avian influenza A (H5N8) in Bulgaria

Published Online: Dec 19, 2019

Page range: 497 - 502

Received: Jun 17, 2019

Accepted: Nov 22, 2019

DOI: https://doi.org/10.2478/jvetres-2019-0073

Keywordspheasants, avian influenza A virus, histopathology, immunohistochemistry, Bulgaria

© 2019 G.M. Stoimenov et al. published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Keywords
pheasants, avian influenza A virus, histopathology, immunohistochemistry, Bulgaria