TABLE 3.
Histopathological lesion and immunohistochemical viral antigen scores for mice intranasally inoculated with H1N1 influenza A viruses and sampled at 6 days p.i.
| Virus strain | Alveolar |
Bronchiolar and bronchial |
Additional lesion features | ||
|---|---|---|---|---|---|
| Histopathology scorea | Viral antigenb | Histopathology scorea | Viral antigenb | ||
| CA/4 | 2.3 | 1.3 | 2 | 1.7 | Histiocytic peribronchiolar alveolitis, some neutrophils; bronchiolitis with some necrosis |
| TX/15 | 1.6 | 0.3 | 1.3 | 0 | Histiocytic alveolitis; bronchiolitis without necrosis |
| Mex/4108 | 1.6 | 1.7 | 2 | 2 | Histiocytic alveolitis with uncommon neutrophils; bronchiolitis without necrosis |
| Mex/4482 | 2.6 | 2 | 2.6 | 1.5 | Histiocytic peribronchiolar alveolitis, common neutrophils; bronchiolitis with some necrosis |
| Mex/4487 | 3 | 1.5 | 3 | 3 | Histiocytic peribronchiolar alveolitis, common neutrophils; histiocytic to neutrophilic bronchiolitis with necrosis |
| NJ/8 | 2 | 1.5 | 2 | 2 | Histiocytic alveolitis; lymphocytic bronchiolitis without necrosis |
| OH/2 | 2.6 | 1.6 | 2.6 | 1.7 | Histiocytic peribronchiolar alveolitis; bronchiolitis with some necrosis |
| 1918 | 3.3 | 3 | 2.5 | 0 | Neutrophilic alveolitis with alveolar epithelial necrosis and edema and interlobular edema; neutrophilic bronchiolitis with severe necrosis |
| VN/1203 | 3.2 | 2 | 2.6 | 2.5 | Neutrophilic peribronchiolar to diffuse alveolitis with edema and histiocytes; neutrophilic bronchiolitis with severe necrosis |
| Mock | 1 | 0 | 1 | 0 | No lesions |
a
Mean histopathological lesion scores for 2 or 3 mice. Histopathological lesion scores per mouse were determined as follows: 1, no lesion; 2, mild lesion; 3, moderate lesion; 4, severe lesion.
b
Mean immunohistochemical viral antigen scores for 2 or 3 mice. Immunohistochemical viral antigen scores per mouse were determined as follows: 0, no antigen; 1, rare positive cells; 2, infrequent positive cells; 3, common positive cells; 4, widespread positive cells.