Table 5 Microscopic lesion scores in lungs of 5 day-old SPF chickens inoculated with field IBV strains IBV/MN, IBV/RA and IBV/TUIBV: infectious bronchitis virus
| Lésions | Mean lesion scores in IBV infected groups of birds | ||||
|---|---|---|---|---|---|
| IBV/MN | IBV/RA | IBV/TU | |||
| Lung | Primary & secondary Bronchi | Epithelial hyperplasia | 2 | 1,7 | 1 |
| Loss of cilia | 1 | 1 | 0,7 | ||
| peribronchial infiltration by mononuclear inflammatory cells | 2 | 1,3 | 0,3 | ||
| Infiltration of lamina propria by heterophils & mononuclear inflammatory cells | 2 | 1,3 | 0,3 | ||
| Atria & parabronchi | Hypertrophy of pneumocytes | 0 | 0,7 | 1,3 | |
| Epithelial hyperplasia | 0 | 0,7 | 1,3 | ||
| Inter-capillarysepta | hyperemia | 1 | 1 | 1 | |
| Mean of total Score of severity | 7.333 | 7.666 | 6 | ||