TABLE 2.
Pathogenicity and replication of H7N2-PR8, TK/VA, and CAN/04 viruses in BALB/c mice
| Viruse | Log10 EID50 required for:
|
Mean virus titerb (log10 EID50/ml) ± SD in:
|
||||
|---|---|---|---|---|---|---|
| MLD50a | MID50 | Lung | Turbinate | Brain | Spleen | |
| H7N2-PR8 | >8.9 | 2.6 | 5.7 ± 0.9c | 3.7 ± 1.0c | NDf | ND |
| TK/VA (H7N2) | >8.2 | 5.8 | 3.7 ± 1.0d | 2.7 ± 1.0d | ND | ND |
| CAN/04 (H7N3) | >8.2 | 4.5 | 4.7 ± 0.8 | NAg | NA | NA |
| NL/219/03 (H7N7) | 2.6 | 0.87 | NA | NA | NA | NA |
a
MLD50, 50% mouse lethal dose.
b
Tissues were harvested on day 4 after inoculation. The lower limit of detection of virus in organs was 1.5 log10 EID50/ml.
c
Virus titers are expressed as the mean for 16 mice inoculated with virus dilutions ranging from 2.9 to 7.9 log10 EID50/ml.
d
Virus titers are expressed as the mean of six mice inoculated with virus dilutions ranging from 5.2 to 7.2 log10 EID50/ml.
e
CAN/04 and NL/219/03 were used for challenge studies.
f
ND, not detected (<1.5 log10 EID50).
g
NA, not applicable.