FIG 9.

Horizontal transmission and respiratory droplet transmission of wtH7N9 and H7N9-K195R viruses in ferrets. Shown are viral titers in nasal washes from ferrets infected with wtH7N9 (A) or H7N9-K195R (B) virus. At 1 dpi, one inoculated ferret was moved to a clean isolator containing a naive ferret in direct contact. Additionally, another naive ferret was placed in the same isolator so that no direct contact was possible, with transmission occurring only via respiratory droplets. To monitor viral shedding, nasal washes were collected from all the animals every other day for 14 days. No data are displayed when the virus was not isolated from all three ferrets. The dashed lines indicate the lower limit of virus detection. Statistical significance relative to H7N9-K195R virus was assessed using two-way ANOVA (*, P < 0.05; **, P < 0.01).