Abstract:

An infectious bursal disease virus (IBDV) field strain, named HQ0806, was isolated and identified from some flocks with immune failure in Fuxin Shi suburb according to the clinical symptom, pathology, serological test, animal challenge and virus morphology. The virus was characterized as a very virulent infectious bursal disease virus (vvIBDV) because of its strong virulence pathogenicity characteristics observed in ELD50 (10-5.8/ 0.2ml), animal challenge (mortality with 83 % and morbidity with 100 % in inoculated 4 weeks chicken), as well as pathological changes of purple grape in bursa of Fabricius, thymus decrease and fatty marrow.