Volume 24, Number 1—January 2018
Research
Characterization of a Feline Influenza A(H7N2) Virus
Table 4
Virus titers in nasal swab samples from cat transmission studies*
Virus |
Transmission mode |
Pair |
Action |
Virus titers in nasal swab samples by days postinfection, exposure, or contact, log10(PFU/mL) | Sero-conversion (HI titer)† | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
1 |
3 |
5 |
7 |
9 |
11 |
13 |
|||||
A/feline/NY/16 | Respiratory droplets | Pair 1 | Infection | 5.6 | 4.7 | 4.3 | 3.0 | – | – | – | 320 |
Exposure |
– |
– |
– |
– |
5.2 |
– |
– |
160 |
|||
Pair 2 | Infection | 4.5 | 2.7 | 5.0 | 4.6 | – | – | – | 320 | ||
Exposure |
– |
– |
– |
– |
– |
5.4 |
– |
80 |
|||
Pair 3 | Infection | 4.8 | 3.2 | 5.3 | 3.6 | – | – | – | 320 | ||
Exposure |
– |
– |
– |
– |
– |
– |
– |
<10 |
|||
Direct contact | Pair 1 | Infection | 5.9 | 4.6 | 3.4 | – | – | – | – | 320 | |
Contact |
– |
– |
2.0 |
5.4 |
– |
– |
– |
320 |
|||
Pair 2 | Infection | 6.0 | 5.0 | 4.6 | – | – | – | – | 640 | ||
Contact |
– |
– |
– |
– |
– |
– |
– |
80 |
|||
Pair 3 | Infection | 4.9 | 4.9 | 4.4 | 4.2 | – | – | – | 640 | ||
Contact |
– |
5.2 |
5.4 |
5.2 |
– |
– |
– |
160 |
|||
A/chicken/NY/99 | Respiratory droplets | Pair 1 | Infection | 4.0 | 3.7 | 4.7 | – | – | – | – | 320 |
Exposure |
– |
– |
– |
– |
– |
– |
– |
20 |
|||
Pair 2 | Infection | – | – | – | – | – | – | – | 320 | ||
Exposure |
– |
– |
– |
– |
– |
– |
– |
20 |
|||
Pair 3 | Infection | 2.6 | 1.6 | 2.3 | – | – | – | – | 80 | ||
Exposure |
– |
– |
– |
– |
– |
– |
– |
160 |
|||
Direct contact | Pair 1 | Infection | 4.5 | 2.4 | 4.5 | – | – | – | – | 80 | |
Contact |
– |
– |
– |
– |
– |
– |
– |
160 |
|||
Pair 2 | Infection | 3.4 | 4.8 | 4.1 | 3.6 | – | – | – | 160 | ||
Contact |
– |
– |
– |
– |
– |
– |
– |
40 |
|||
Pair 3 | Infection | 3.4 | 3.5 | 3.2 | 3.3 | – | – | – | 160 | ||
Contact | – | – | – | – | – | – | – | 20 |
*–, no virus detected.
†Serum samples were collected on day 18 after infection, exposure, or contact, and examined by use of an HI assay. The HI titer is the inverse of the highest dilution of serum that completely inhibited hemagglutination.
1These authors contributed equally to this article.