title: Very Virulent Infectious Bursal Disease Virus Produces More-Severe Disease and Lesions in Specific-Pathogen-Free (SPF) Leghorns Than in SPF Broiler Chickens.
abstract: Infectious bursal disease virus (IBDV) is an important pathogen of chickens causing negative economic impacts in poultry industries worldwide. IBDV has a variable range of virulence, with very virulent (vvIBDV) strains being responsible for the greatest losses from mortality and decreased performance. Previous vvIBDV studies using conventional broilers reported resistance to lethal effects and decreased performance as compared to specific-pathogen-free (SPF) layers, but the potential contribution of the conventional vs. SPF status to resistance has not been examined. In this study we compared differences in the acute pathologic effects of infection by the California rA strain of vvIBDV for SPF white leghorn egg-laying chickens and SPF white Plymouth Rock broiler chickens over a 7-day experimental period. Based on the clinical signs and mortality observed, as well as on the more-severe pathologic changes in lymphoid tissues and kidneys, white leghorns were shown to be more susceptible to the deleterious effects of vvIBDV infection than were white Plymouth Rocks. This study provides important information on the impact of chicken breed on susceptibility to vvIBDV and the absence of impact from conventional vs. SPF status on the outcome.
authors.affiliation: A Southeast Poultry Research Laboratory, United States National Poultry Research Center, Agricultural Research Service, United States Department of Agriculture, 934 College Station Road, Athens, GA 30605.
authors.forename: Mariana
authors.initials: M
authors.lastname: Sá e Silva
authors.affiliation: B Department of Pathology and Athens Veterinary Diagnostic Laboratory, College of Veterinary Medicine, The University of Georgia, Athens, GA, 30606.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Rissi
authors.affiliation: A Southeast Poultry Research Laboratory, United States National Poultry Research Center, Agricultural Research Service, United States Department of Agriculture, 934 College Station Road, Athens, GA 30605.
authors.forename: David E
authors.initials: DE
authors.lastname: Swayne
mesh_terms: D000818:Animals; D018175:Birnaviridae Infections / Q000235:genetics / Q000662:veterinary* / Q000821:virology; D002645:Chickens; D005260:Female; D007243:Infectious bursal disease virus / Q000472:pathogenicity* / Q000502:physiology*; D011201:Poultry Diseases / Q000235:genetics / Q000821:virology*; D013047:Specific Pathogen-Free Organisms; D014774:Virulence
keywords: broiler; chicken; infectious bursal disease virus; layer; pathogenesis; rA strain; very virulent infectious bursal disease virus; white Plymouth rock; white leghorn