TABLE 4.
Virus titers in nasal washes of inoculated and contact ferrets and seroconversion titers
| Virus (type) | Pair | Ferret groupa | Virus titer (log10 PFU/ml) in nasal wash on day: |
Seroconversion (HI titer)b | |||||
|---|---|---|---|---|---|---|---|---|---|
| 1 | 3 | 5 | 7 | 9 | 11 | ||||
| A/Sapporo/114/2013 (H275Y mutant) | 1 | I | 7.7 | 4.6 | 3.1 | —c | — | — | 1,280 |
| C | 4.5 | 5.1 | 5.3 | — | — | — | 1,280 | ||
| 2 | I | 7.6 | 3.7 | 3.4 | — | — | — | 1,280 | |
| C | — | — | — | 6.0 | 3.8 | — | 1,280 | ||
| 3 | I | 7.7 | 3.3 | 4.7 | 1.0 | — | — | 640 | |
| C | — | — | 6.5 | 3.6 | — | — | 1,280 | ||
| A/Shizuoka-c/99/2013 (wild type) | 1 | I | 7.3 | 5.3 | 4.3 | — | — | — | 2,560 |
| C | — | — | — | — | — | — | <10 | ||
| 2 | I | 7.3 | 5.4 | 5.3 | — | 2,560 | |||
| C | — | — | — | — | — | — | <10 | ||
| 3 | I | 7.8 | 5.3 | 4.1 | — | — | — | 2,560 | |
| C | — | 5.7 | 4.6 | 2.1 | — | — | 1,280 | ||
a
For each pair of ferrets, one animal was intranasally inoculated with 0.5 ml of 106 PFU virus (inoculated ferret [I]) and 24 h later, a naive ferret was placed in an adjacent cage (contact ferret [C]). Nasal washes were collected from inoculated and contact ferrets every other day for virus titration.
b
Hemagglutination inhibition (HI) assays were carried out with A/Sapporo/114/2013 virus and turkey red blood cells.
c
—, virus not detected (detection limit, 1.3 log10 PFU/ml).