Table 2.
Detailed assay results for birds positive for WNV RNA*
| Bird no. | Species† | Weeks PI‡ | WNV genotype | Mean peak viremia§ | PRNT90 antibody titer¶ | Organs positive for WNV RNA (Ct)# |
|---|---|---|---|---|---|---|
| 434 | House Finch | 28 | NY99 | 7.5 (3) | 1:320 | Spleen (33.6, UD) |
| 435 | House Finch | 28 | NY99 | 7.5 (3) | 1:1280 | Spleen (33.7, UD), kidney (28.8, 29.5) |
| 436 | House Finch | 28 | NY99 | 7.2 (3) | 1:320 | Spleen (31.6, UD) |
| 408 | House Finch | 28 | TM 171-03 pp1 | 4.3 (3) | 1:80 | Kidney (33.2, 35.2) |
| 409 | House Finch | 28 | TM 171-03 pp1 | 4.9 (3) | 1:40 | Spleen (33.3, UD) |
| 414 | House Finch | 28 | TM 171-03 pp1 | 4.0 (3) | 1:80 | Kidney (27.2, UD) |
| 417 | House Finch | 28 | TM 171-03 pp1 | 54 (4) | 1:10 | Spleen (35.2, 39.1) |
| 423 | House Finch | 28 | TM 171-03 pp1 | 1.7 | 1:5 | Spleen (35.7, UD) |
| 30 | House Sparrow | > 18 | Naturally infected | NT | 1:320 | Spleen (36.9, UD) |
| 176 | House Sparrow | > 18 | Naturally infected | NT | NS | Spleen (34.3), kidney (29.9) |
| 193 | House Sparrow | > 18 | Naturally infected | NT | < 1:5 | Spleen (33.1) |
| 308 | House Sparrow | > 18 | Naturally infected | NT | 1:320 | Spleen (32.2) |
| 171 | House Sparrow | 28 | NY99 | 6.4 (2) | 1:320 | Spleen (35.1) |
| 256 | House Sparrow | 31 | NY99IC point mutant | 4.5 (4) | 1:640 | Spleen (31.0) |
| 277 | House Sparrow | 31 | NY99IC point mutant | 4.7 (5) | 1:320 | Spleen (34.2), kidney (30.8) |
| 300 | House Sparrow | 31 | NY99IC point mutant | 5.3 (2) | 1:40 | Spleen (32.6) |
| 302 | House Sparrow | 31 | NY99IC point mutant | 2.7 (3) | 1:320 | Kidney (32.7) |
| 207 | House Sparrow | 36 | TM 171-03 pp1 | 1.7 | 1:1280 | Spleen (33.7, UD) |
| 163 | House Sparrow | 28 | TM 171-03 pp1 | 5.1 (3) | 1:640 | Kidney (30.9) |
| 168 | House Sparrow | 28 | TM 171-03 pp1 | 2.4 (3) | 1:320 | Kidney (31.9) |
| 182 | House Sparrow | 28 | TM 171-03 pp1 | 1.7 | < 1:5 | Kidney (34.3) |
| 209 | House Sparrow | 36 | TM 171-03 pp5 | 5.0 (2) | 1:320 | Spleen (37.3, 38.3) |
| 6845 | Western Scrub-Jay | > 18 | Naturally-infected | NT | 1:320 | Spleen (34.1, UD) |
| 6852 | Western Scrub-Jay | > 18 | Naturally infected | NT | 1:40 | Spleen (33.7, UD), kidney (35.7, UD) |
WNV = West Nile virus.
House Finch (Carpodacus mexicanus); House Sparrow (Passer domesticus); Western Scrub-Jay (Aphelocoma californica).
PI = post-infection. Time PI for naturally infected birds was unknown but was > 18 weeks post-collection.
Peak viremia was measured in log10 plaque-forming units (pfu)/mL of serum by Vero cell plaque assay; day post-infection for which peak viremia was measured is shown in parentheses; NT = not tested; 1.7 log10 pfu/mL was the detection limit for this assay.
PRNT90 = plaque reduction neutralization titer. Shown is the highest serum dilution at which 90% of > 75 plaque-forming units of WNV were neutralized. The highest serum dilution tested was 1:5.
Tissues were tested for WNV RNA by using reverse transcription–polymerase chain reaction and primers and a probe specific for the envelope region of the viral genome (WN1). Taqman cycle threshold (Ct) score is shown in parentheses. When two Ct scores are present, the second result was extracted from tissue homogenate used for viral isolation; UD = undetermined, i.e., Ct > 40.