FIG 1.
Experiment settings for chicken-to-chicken and chicken-to-ferret transmission. Donor chickens (n = 3; middle shelf) were inoculated via a natural route with 5 ×106 EID50s of the SCk1772 or HK3263 virus. An additional 6 chickens (bottom shelf) were inoculated with SCk1772 or HK3263 virus for pathology examinations at 2, 4, and 6 dpi (data not shown). At 1 dpi, two direct-contact chickens were introduced and cohoused with the three inoculated donors; in addition, three naive airborne-contact chickens were introduced to the adjacent cage to evaluate the airborne-transmission efficiency of SCk1772 or HK3263. The airborne-contact chickens were separated from the donors and direct-contact chickens with a perforated (0.5-cm holes separated by 1 cm) stainless steel divider (dotted blue line). Two naive ferrets were introduced at 1 dpi and were housed separately above the chickens. The two ferrets were separated with a solid stainless steel divider (solid blue line).