FIG 2.

WT H7N1 shows limited transmission to CH animals in the absence of virus shedding. Four ferrets received 1 × 10⁶ TCID₅₀ of WT H7N1 virus. At 24 hpi, a CH and an AC ferret were introduced to each DI animal. Nasal wash fluid samples were collected daily for virus titration. Viral titers and weight losses of DI (A), CH (B), and AC (C) ferrets. Red (blue, green, or pink) corresponds to one experimental cage setup consisting of three ferrets (one DI, one CH, and one AC ferret) housed in the same isolator. In parentheses is the proportion of ferrets that succumbed to infection or were euthanized. Daggers denote animals that were euthanized or succumbed to infection. N denotes neurological symptoms.