Figure 10. Viral loads (RNA genome equivalents per mL nasal wash or per g lung tissue) for each donor ferret on dpi 1 or dpi 3.

Necropsy of donor was performed 2 h after exposing recipient ferrets. Data combined from 3 experiments indicated by circles, triangles and diamonds. Lung tissue viral RNA levels for Cal/04 were mean (SD) = 5.94 (2.72) compared to Cal/07+Mex/4482 lung RNA mean (SD) = 8.84 (1.42), significant by t test at p = 0.007. Aerosol transmission success for each virus is exhibited in Figures 4 and 7. The NC/99-infected donors did not have viral RNA in lung tissue nor transmitted infection by exhaled aerosol.