Volume 10, Number 12—December 2004
Research
Differential Virulence of West Nile Strains for American Crows
Table 2
Clinical profile of American Crows infected with WNV strains NY99 (strain NY99-4132), KEN (strain KEN-3829), and KUN (strain KUN-6453)
Virus group | Mortality: no. died /N (%) | Morbidity: no. ill/N (%) | Mean day of death ± SD | Mean peak viremiaa ± SD (mean duration ± SD) (n) | Mean day of peak viremiaa ± SD |
---|---|---|---|---|---|
NY99 | 8/8 (100) | 8/8 (100) | 5.1 ± 0.6 | 9.2 ± 1.2 (4.2 ± 0.7) (8) | 4.3 ± 0.9 |
KEN | 1/8 (12.5) | 2/8 (25) | 9 ± NA | 7.5 ± 0 (4.5 ± 0.7) (2) | 5.0 ± 1.4 |
KEN-hdb | 2/8 (25) | 3/8 (38) | 10.5 ± 2.1 | 4.8 ± 0.6 (3.1 ± 0.8) (8) | 5.5 ± 0.9 |
KUN | 0/8 | 0/8 | NA | 4.2 ± 0.8 (1.8 ± 0.5) (8) | 3.3 ± 0.7 |
Control | 0/8 | 0/8 | NA | NA | NA |
aViral titers were expressed as the log10 PFU/mL of crow sera as determined by plaque assay on Vero cells.
bhd, high-dose group (6,000 [3.8 log10] PFU); NA, not applicable.