Fowl typhoid has been known as acute septicaemic disease of chickens, which occurs in adult birds mostly in subacute-chronic form, and mainly in household flocks. In 2006 and 2007 the authors detected acute septicaemic form of the disease with 1-5% daily mortality in 6 (17 weeks -19 months old, a number of 2000-11000) laying hen flocks of 5 owners. With post mortem examination necrotic foci in the swollen spleen and liver, multiplex focal myocarditis, renal and follicular degeneration and catarrhal enteritis were diagnosed. In the smaller foci coagulation necrosis of parenchyma cells, in the larger foci around the necrosis inflammatory cells (heterophil granulocytes, lymphocytes and macrophages) were detected, as well. In the myocardium, in the field of inflammatory cell infiltration myocyte degeneration and necrosis could be found. Salmonella bacteria were detectable with immunohistochemical examination, extracellularly in the blood vessels and in the cytoplasm of macrophages, in the necrotic foci, and in the field of myocarditis, in groups. With polymerase chain reaction a pattern typical to S. Gallinarum virulence piasmid (spvC gene was detectable, pefA gene was missing). In the respect the strains were homogenous. By pulse field electrophoresis the pattern of strains showed 90% similarity, indicating genetic relationship and possible epidemic link (common origin), and possible spread by egg trays. In the animals anaemia and Dermanyssus gallinae infestations were dignosed in more cases. S. Gallinarum was isolated in two cases from D. gallinae homogenisate collected from the pen of diseased hens, which may explain the occurrence of the disease in the flocks introduced into the pens left empty for months. Authors suggest that renewed and more rigorous regulations (separate from the present Hungarian Salmonella order focusing on S. Enteritidis, and S. Typhimurium) should be formulated in order to prevent re-emergence of fowl typhoid (a long ago eradicated disease) in Hungary.
|Translated title of the contribution||Acute epidemic disease in laying hen flocks, caused by Salmonella Gallinarum|
|Number of pages||7|
|Journal||Magyar Allatorvosok Lapja|
|Publication status||Published - Oct 27 2008|
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