Table 3.
Summary results for birds grouped by mean peak viremia for WNV*
| Species† | Peak viremia titer range | No. | Mean peak viremia‡ | Geometric mean antibody titer§ | PRNT90 titer range | No. (%) WNV RNA positive¶ |
|---|---|---|---|---|---|---|
| House Finch | 0–3.0 | 3 | 2.2 | 1:25 | 1:320–1:1,280 | 1 (33) |
| 3.1–5.0 | 6 | 4.5 | 1:71 | 1:5–1:160 | 3 (50) | |
| 5.1–8.0 | 6 | 6.8 | 1:285 | 1:10–1:1,280 | 4 (67) | |
| Naturally infected | 1 | NT | 1:1,280 | 1,280 | 0 | |
| House Sparrow | 0–3.0 | 12 | 2.2 | 1:226 | 1:80–1:320 | 5 (42) |
| 3.1–5.0 | 6 | 4.4 | 1:160 | < 1:5–1:1,280 | 3 (50) | |
| 5.1–8.0 | 11 | 5.8 | 1:219 | 1:80–1:640 | 3 (27) | |
| Naturally infected | 9 | NT | 1:101 | 1:160–1:640 | 4 (44) | |
| Western Scrub-Jay | Naturally infected | 2 | NT | 1:113 | 1:40–1:320 | 2 (100) |
WNV = West Nile virus.
House Finch (Carpodacus mexicanus); House Sparrow (Passer domesticus); Western Scrub-Jay (Aphelocoma californica).
Mean peak viremia represented in log10 plaque-forming units/mL of serum. Viremia titers of naturally infected birds were unavailable and not tested (NT).
Tested by plaque reduction neutralization test (PRNT). Shown is the highest serum dilution at which 90% of > 75 plaque-forming units of WNV were neutralized. The lowest serum dilution tested was 1.5.
Spleen and kidney tissue were screened for WNV RNA by using quantitative reverse transcription–polymerase chain reaction and primers and a probe specific for the envelope region of the viral genome (WN1).