Fig. 3: Comparison of the respiratory tract pathology of SARS-CoV-2 Infected hamsters.

Comparison of SARS-CoV-2 pathology for intranasal (I.N.), aerosol and fomite inoculated hamsters at 4 day post inoculation (DPI) (N = 4). a Infiltration and disruption of the ciliated nasal mucosa by moderate numbers of leukocytes with multifocal epithelial cell necrosis (200x; bar = 100 µm). b Multifocal disruption of the nasal ciliated mucosa by low numbers of leukocytes with accumulations of degenerate leukocytes in the nasal passage (200x; bar = 100 µm). c Intact ciliated nasal mucosa with normal mucus presence within the lumen (200x; bar = 100 µm). d A control nasal turbinate with intact ciliated nasal mucosa and mucus within the lumen (200x; bar = 100 µm). e Disruption of the tracheal mucosa with single cell necrosis and infiltration by low numbers of leukocytes (400x; bar = 50 µm). f Unaffected tracheal mucosa (400x; bar = 50 µm). g Unaffected tracheal mucosa (400x; bar = 50 µm). h Section of tracheal mucosa from a control hamster (400x; bar = 50 µm). i–l No significant histopathologic lesions in the lung of any inoculation route at 1 day-post-inoculation (100x; bar = 200 µm). m Multifocal disruption of ciliated nasal mucosa with accumulation of cellular debris and degenerate leukocytes within the nasal passage (200x; bar = 100 µm). n Severe disruption and multifocal erosion of the nasal mucosa with accumulation of numerous degenerate leukocytes and abundant cellular debris within the nasal passage (200x; bar = 100 µm). o Ciliated epithelial cell degeneration and mucosal erosion with leukocyte infiltration into the lamina propria (200x; bar = 100 µm). p Normal nasal turbinate from a control hamster (200x; bar = 100 µm). q Focal disruption of the tracheal mucosa by low numbers of leukocytes (400x; bar = 50 µm). r Multifocal infiltration of the mucosa by moderate numbers of leukocytes and multifocal epithelial cell necrosis (400x; bar = 50 µm). s Multifocal loss of epithelial cilia and infiltration of the lamina propria by moderate numbers of leukocytes (400x; bar = 50 µm). t Normal tracheal mucosa from a control hamster (400x; bar = 50 µm). u Widespread, moderate to severe broncho-interstitial pneumonia (100x; bar = 200 µm). v Multifocal moderate broncho-interstitial pneumonia focused on terminal bronchioles (100x; bar = 200 µm). w Multifocal, mild interstitial pneumonia focused on terminal bronchioles (100x; bar = 200 µm). x Normal lung from a control hamster (100x; bar = 200 µm). y, z Clustering (Euclidean, complete) of animals based on viral titers in lung and trachea and quantitative assessment of pathology in the upper and lower respiratory tract on 1 DPI and 4 DPI. Heatmap colors refer to color scale on the right, gray = NA, I.N. = red, Aerosol = blue, Fomite = purple, Control = black. Exposure route is indicated by color bar at the top. Source data are provided as a Source Data file.