TY - JOUR
T1 - An unusual case of haemorrhagic bursa in a pullet flock associated with a genogroup 2 infectious bursal disease virus
AU - Higgins, Jessica
AU - Wallner-Pendleton, Eva
AU - Michel, Linda
AU - Jackwood, Daral
N1 - Publisher Copyright:
© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
PY - 2021
Y1 - 2021
N2 - An unusual case of infectious bursal disease (IBD) was observed in eight-week-old commercial caged pullets. This flock (House 1) exhibited a one-day spike in mortality. On gross necropsy examination, enlarged, diffusely haemorrhagic bursas were observed. This lesion has been frequently described in cases of very virulent infectious bursal disease virus (vvIBDV). A five-week-old caged pullet flock (House 2) in an adjacent building did not display haemorrhagic bursa lesions. Microscopic examination of bursas from the eight-week-old pullets in House 1 showed marked diffuse haemorrhages and extensive lymphoid necrosis. Histopathology of bursas from the five-week-old pullets in House 2 showed severe, diffuse lymphoid depletion without haemorrhages. IBD ELISA results from birds in House 1 at 9 weeks had a GMT of 6395 and birds in House 2 had a GMT of 82 in the same timeframe. Diagnostic testing for avian influenza virus, Mycoplasma gallisepticum, Mycoplasma synoviae, virulent Newcastle disease virus, infectious bronchitis virus, infectious laryngotracheitis virus, chicken anaemia virus and fowl pox virus were negative. The predicted amino acid sequence of the hypervariable region of VP2 indicated the IBDV observed in both flocks (1/chicken/USA/1300OH/19 from House 1 and 1/chicken/USA/1301OH/19 from House 2) was identical and was not a vvIBDV. Their sequences were similar to a genogroup 2 IBDV from Ontario, Canada (EF138967). No mortality was observed when the 1/chicken/USA/1300OH/19 virus was inoculated into specific-pathogen-free (SPF), four-week-old pullets. Gross and microscopic lesions were observed in bursa tissue, but the bursal haemorrhages observed in the original field case were not reproduced in challenged SPF pullets.
AB - An unusual case of infectious bursal disease (IBD) was observed in eight-week-old commercial caged pullets. This flock (House 1) exhibited a one-day spike in mortality. On gross necropsy examination, enlarged, diffusely haemorrhagic bursas were observed. This lesion has been frequently described in cases of very virulent infectious bursal disease virus (vvIBDV). A five-week-old caged pullet flock (House 2) in an adjacent building did not display haemorrhagic bursa lesions. Microscopic examination of bursas from the eight-week-old pullets in House 1 showed marked diffuse haemorrhages and extensive lymphoid necrosis. Histopathology of bursas from the five-week-old pullets in House 2 showed severe, diffuse lymphoid depletion without haemorrhages. IBD ELISA results from birds in House 1 at 9 weeks had a GMT of 6395 and birds in House 2 had a GMT of 82 in the same timeframe. Diagnostic testing for avian influenza virus, Mycoplasma gallisepticum, Mycoplasma synoviae, virulent Newcastle disease virus, infectious bronchitis virus, infectious laryngotracheitis virus, chicken anaemia virus and fowl pox virus were negative. The predicted amino acid sequence of the hypervariable region of VP2 indicated the IBDV observed in both flocks (1/chicken/USA/1300OH/19 from House 1 and 1/chicken/USA/1301OH/19 from House 2) was identical and was not a vvIBDV. Their sequences were similar to a genogroup 2 IBDV from Ontario, Canada (EF138967). No mortality was observed when the 1/chicken/USA/1300OH/19 virus was inoculated into specific-pathogen-free (SPF), four-week-old pullets. Gross and microscopic lesions were observed in bursa tissue, but the bursal haemorrhages observed in the original field case were not reproduced in challenged SPF pullets.
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U2 - 10.1080/03079457.2021.1912287
DO - 10.1080/03079457.2021.1912287
M3 - Article
C2 - 33823706
AN - SCOPUS:85105155398
VL - 50
SP - 269
EP - 276
JO - Avian Pathology
JF - Avian Pathology
SN - 0307-9457
IS - 3
ER -