New Introduction of a Very Virulent Infectious Bursal Disease Virus in New York, USA.

New Introduction of a Very Virulent Infectious Bursal Disease Virus in New York, USA. Avian Pathol. 2019 Jun 03;:1-20 Authors: Michel LO, Kimber ML, Jackwood DJ Abstract Bursa tissue samples from a pullet flock in New York State that was experiencing immune suppression related disease were sent to our laboratory in 2018. A very virulent infectious bursal disease virus (vvIBDV) was identified in those samples through molecular and pathogenicity studies and designated 1/chicken/USA/1054NY/18. Phylogenetic analyses of the hypervariable VP2 nucleotide sequence region indicated that this strain belonged to genogroup 3 which comprises the vvIBDV. Partial sequence data of the VP1 gene indicated this virus also had a VP1 typical of vvIBDV. While vvIBDV have previously been identified in the United States in California and Washington State, the 1054NY vvIBDV was most closely related to isolates from Ethiopia, suggesting it is a new introduction into the U.S. The 1054NY vvIBDV was used to challenge four-week old specific-pathogen-free (SPF) layer chicks where it caused 100% morbidity and 68.7% mortality within four days. Upon necropsy, gross pathological findings in infected SPF birds included small yellowish colored bursas, some with hemorrhages on the serosal and mucosal surfaces. Microscopic lesions included inflammation, severe lymphocyte necrosis, atrophy of the follicles and follicular depletion of lymphocytes. Research Highlights: A ver...
Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research