TABLE 3.
Pathogenicity and infectivity of H7N2-PR8 and TK/VA in chickens
| Inoculation route | Virus | Challenge dose (log10 EID50/ml) | Mobidity (no. of chickens sick/total no.) | Mortality (no. of chickens dead/total no.) | No. of chickens that seroconverted/total no. bya:
|
Virus isolationb (log10 EID50/ml) from:
|
||
|---|---|---|---|---|---|---|---|---|
| AGP | HI | Oropharynx | Cloaca | |||||
| i.v.e | H7N2-PR8 | 7.9 | 0/8 | 0/8 | 8/8 | 8/8 | NAd | NA |
| TK/VA | 7.1 | 0/8 | 0/8 | 8/8 | NDc | NA | NA | |
| i.n. | H7N2-PR8 | 5.5 | 0/8 | 0/8 | 5/8 | 6/8 | 1.8 (8/8) | NA (0/8) |
| TK/VA | 6.5 | 0/8 | 0/8 | 8/8 | ND | 4.6 (8/8) | 1.0 (1/8) | |
| None | Sham | NA | 0/4 | 0/4 | 0/4 | 0/4 | NA | NA |
a
The HI test used homologous HI antigen (β-propiolactone inactivated). Chickens were sacrificed 14 days after inoculation, and sera were harvested.
b
Virus titers are expressed as means from eight chickens. The negative threshold for swab samples is <0.9 log10 EID50/ml. Values in parentheses are numbers of chickens sampled/total number of chickens in the group.
c
ND, not done.
d
NA, not applicable.
e
i.v., intravenous.