Table 1.

Clinical signs, virus replication, seroconversion, and transmission in ferrets inoculated with WT influenza viruses

VirusSubtypeNo. of inoculated ferrets/total number
No. of contact ferrets/total number
Clinical signs
Peak mean log10 nasal wash titer (day p.i.)Seroconversion (HI titer range) Virus detected in nasal washSeroconversion (HI titer range)
Weight loss (%)*Sneezing (day of onset)
Pan99H3N23/3 (7.9)3/3 (2)6.9 (1)3/3 (1,280–2,560)3/33/3 (20–640)Efficient (RD)
Vic75H3N23/3 (9.5)3/3 (2)7.8 (1)3/3 (160–320)3/33/3 (40–1,280)Efficient (RD)
HK486H5N13/3 (16.5)1/3 (4)7.0 (5)2/2 (1,280)0/32/3 (160–320)Inefficient (RD)
HK213H5N13/3 (8.8)0/35.5 (1, 3)2/2 (1,280)0/30/3None (RD)
Indon05H5N13/3 (18.8)0/36.6 (3)ND § 0/30/3None (C)
VN30408H5N13/3 (9.9)0/35.2 (3)3/3 (40–160)0/30/3None (C)
  • RD, respiratory droplet; C, contact transmission.

  • *The percentage mean maximum weight loss is shown.

  • HI assays were performed with homologous virus and RBCs derived from either horse for H5 viruses or turkey for H3 viruses.

  • Only two ferrets survived and were tested.

  • §ND, not determined because no ferrets survived beyond 7 days p.i.