Real-time RT-PCR results (based on 15 µl swab fluids), GEC values and TCID₅₀ (both based on 100 µl swab fluids) of tracheal and cloacal samples obtained from ducks after challenge with HPAIV H5N1 strain.

*The numbers indicate days post-challenge (dpc). 1Number of positive birds as indicated by real-time RT-PCT. Ct-values<36 considered as positive. 2Average ct-value of positive ducks per 15 µl of swab fluid. 3The max and min range of positive ct-values. 4Average genome equivalent copy (GEC) number of positive samples/100 µl of swab fluid. 5Average tissue culture infectious dose (TCID50) titre/100 µl of swab fluid. 6At this stage one of the control birds died. 7Two ducks lost the wing tags at 5 dpc, and one of them died at 5 dpc, since their assignment to either H4 or control groups was not possible, both were excluded from calculations after day 5.