Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/18/2008
Publication Date: N/A
Technical Abstract: Myocarditis associated with Reovirus in Turkey Poults H. L. ShivaprasadA, M. S. FrancaA, P. R. WoolcockA, R. NordhausenB, M. DayC and M. Pantin-JackwoodC California Animal Health and Food Safety Laboratory System, AFresno and BDavis Branches, University of California, Davis, 2789 South Orange Ave, Fresno, CA 93725 CSoutheastern Poultry Research Laboratory, U S Department of Agriculture, Agriculture Research Laboratory Service, 934 College Station Road, Athens, GA 30605 Myocarditis associated with Reovirus was diagnosed in 17- day - old male turkey poults based on virus isolation in chicken egg embryos, reverse transcript – polymerase chain reaction and demonstration of reovirus antigen in the cytoplasm of mononuclear inflammatory cells and myocytes in the heart and in other organs by immunohistochemistry. Clinical signs in the poults included anorexia, growth depression and increased mortality. Gross lesions in the six poults examined included increased pericardial fluid, mild to moderate dilation of right ventricles and pale yellow myocardium and ascites. Other lesions in a few birds included mild pulmonary edema and congestion and pale serosa of the small intestine that contained watery contents in their lumens. Microscopically in the heart there was mild to severe necrosis of myocytes and infiltration of primarily lymphocytes mixed with a few heterophils, macrophages and occasionally plasma cells and multinucleated giant cells. There was mild to moderate lymphoid depletion in the bursa of Fabricius. Reovirus particles were demonstrated in the endoplasmic reticulum of cardiac myocytes by transmission electron microscopy. Retrospective search of CAHFS data base for cases of myocarditis associated with reovirus in turkeys revealed that this condition has occurred sporadically since 1991.