Table 4 Microscopic lesion scores in trachea of 5 day-old SPF chickens inoculated with field IBV strains IBV/MN, IBV/RA and IBV/TUIBV infectious bronchitis virus
Lesions | Mean lesion scores in IBV infected groups of birds | ||||
|---|---|---|---|---|---|
IBV/MN | IBV/RA | IBV/TU | |||
Trachea | Epithelium | Thickening | 1 | 1,3 | 2 |
Hyperplasia (1-4 +) | 1 | 1,3 | 2,6 | ||
Loss of cilia | 0 | 0 | 0,6 | ||
Degenerescence and necrosis of epithelial cells | 0 | 0 | 0 | ||
Inflammatory exudate (degenerate epithelial cells, Lc, heterophyles) on the surface | 0 | 0,3 | 0,6 | ||
Lamina propria | Oedema, | 0 | 0,6 | 1 | |
Diffuse infiltration by mononuclear inflammatory cells (Lc, Plc, Mph) | 1,3 | 1,3 | 1,3 | ||
Mean total Score of severity | 3.666 | 4.666 | 7,666 | ||