Figure 3

<strong>Figure 3. Infectious viral shedding in nasal washes from ferrets infected with WT or NA-H275Y+PA-I38T clinical isolates and in ferrets infected by airborne virus exposure.</strong> Donor ferrets (n=4) were infected by the intranasal route with 5 log10TCID50/mL of pure WT or NA-H275Y+PA-I38T clinically isolated virus and co-housed with naïve recipient ferret 1 (RF1) separated by an airborne virus-permeable barrier at day 1 (D1) post inoculation. Infected RF1s were then co-housed with RF2 ferrets, enabling a second airborne transmission event to occur. Viral titre mean from nasal washes from donor (a), RF1 (b) and RF2 ferrets (c), by TCID50 assay. Fractions above each symbol represent the number of ferrets shedding virus above LOD (dotted horizontal line), all values below LOD equal zero. No statistically significant (adjusted p&lt;0.05) differences was observed (Sidak’s Two-way ANOVA multiple comparisons). (d) Area under the curve analysis was performed for each individual ferret (n=4) and overall viral shedding was compared between WT (black) and NA-H275Y+PA-I38T (D.Mt, red). (e) Duration of infectious viral shedding above LOD was tallied for each ferret. (f) Estimation plot of the combined duration of viral shedding for all donor, RF1 and RF2 ferrets was analysed by Unpaired t-test to display a 95% confidence interval of the difference between the mean duration of shedding for WT and NA-H275Y+PA-I38T infected ferrets.