NOVEL STRAIN OF MAREK'S DISEASE EMERGES IN US FLOCK

摘要

Dr. John K. Rosenberger and Dr. Sandra C. Rosenberger, in cooperation with Milos Markis of the University of Delaware, evaluated an outbreak of Marek's disease with an unusual presentation. The condition was observed during late winter of 2010 extending into the spring of 2011. Marek's disease virus was isolated from affected layers. The condition was characterised by elevated mortality in pullets and losses continued subsequent to transfer to layer houses. A number of laying strains were affected and the clinical signs included characteristic paralysis. In some cases tumours occurred in pullets without any apparent involvement of the nervous system. Concurrently a similar presentation was observed in broiler flocks in Pennsylvania.