Nasal shedding and direct contact transmission of wild bird influenza viruses in ferrets.

Seven ferrets were intranasally inoculated with 5×10⁵ PFUs of either H6N1 (A) or H1N9 (B) and nasal washes were collected and titered on MDCK cells (days post-inoculation portion of graph). Three naïve ferrets were paired with three of the inoculated ferrets 24 hours post inoculation for each virus group (days post-direct contact portion); nasal washes were collected titered on MDCK cells. Both H6N1 and H1N9 demonstrated replication in the upper respiratory tract of the ferrets, however, viral shedding was consistently greater in magnitude and duration for H1N9. H1N9 demonstrated direct contact transmission, but H6N1 did not transmit to direct contact ferrets.