Figure 4

Pulmonary pathology in the infant (open circles) and adult (closed diamonds) cotton rats infected with A/Wuhan/359/95 on days 1, 2, 3, 4 and 7 p.i. Results are reported as arithmetic means of histopathology scores that have been transformed to a scale of 0 to 100, reflecting the degree of epithelial cell damage, amount of exudate present in the small and large airways, and the extent of peribronchiolitis and interstitial pneumonitis observed in hematoxylin and eosin-stained lung sections, for 4 animals per group. SEM is indicated at each time point. The time points at which the degree of pathology was significantly different (independent samples t test, p < 0.05) between adult and infant lungs are indicated with an asterisk (*) beneath the x axes.