Serum antibody titers and viral detection in the H5N1 HPAI virus-inoculated (group 1) and acute stage contact (group 2) ducks.

<p>Five ducks inoculated with H5N1 HPAI virus (group 1) and five naive contact ducks (group 2) were mixed at one day post inoculation (dpi). Sera were collected at 4 days pre-inoculation for both groups and at 8 and 15 dpi (equivalent to 7 and 14 days post contact (dpc) respectively for group 2). Sera were tested with blocking ELISA (values are % inhibition; cut-off = 60%), HI using chicken RBCs (HI-C) and horse RBCs (HI-H), and virus neutralization (VN) tests. nd: not done.</p><p>^a Summary of virus isolation (VI): a+symbol indicates that virus was isolated at least once from either oral or cloacal swab from the duck during the duration of the trial.</p><p>^b Summary of Ct values for real-time reverse transcription polymerase chain reaction (rRT-PCR) results: the value is the lowest detected for the duck from either oral or cloacal swabs during the duration of the trial.</p><p>^c Ducks 94 and 85 developed disease during the experiment; therefore the last sera were obtained when they were euthanized, for welfare reasons, at 5 dpc (shown under 8 dpi) and 9 dpc (shown under 15 dpi), respectively.