Volume 9, Number 3—March 2003
Research
Experimental Infection of North American Birds with the New York 1999 Strain of West Nile Virus
, Stanley Langevin*, Steven Hinten*, Nicole M. Nemeth*†, Eric Edwards*†, Danielle L. Hettler*†, Brent S. Davis*, Richard A. Bowen†, and Michel L. Bunning*‡
Table 7
West Nile virus shedding in living birds, as determined by plaque assay of oral swabs collected daily from 14 species of birds exposed by mosquito bitea,b
| Species | n | Day postinoculation |
No. birds shedding (%) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | |||
| American Kestrelc |
2 |
1.2 (1.0–1.3) |
1.9 (1.6–2.1) |
3.9 (3.0–4.2) |
4.1 (2.8–4.4) |
4.9 (4.6–5.1) |
5.1 (4.6–5.3) |
3.3 (3.1–3.4) |
2 (100) |
| Northern Bobwhite |
3 |
<–0.2 |
<–0.2 |
0.2 (<0.4–0.3) |
<–0.2 |
<–0.2 |
<–0.2 |
<–0.2 |
1 (33) |
| Japanese Quail |
3 |
<–0.2 |
<–0.2 |
<–0.2 |
<–0.2 |
<–0.2 |
2.5 (<0.4–3.0) |
1.9 (<0.4–2.4) |
1 (33) |
| Killdeer |
2 |
NT |
<0.1 |
0.4 (<0.4–0.7) |
0.1 (<0.4–0.4) |
0.8 (<0.4–1.1) |
0.1 (<0.4–0.4) |
0.4 (<0.4–0.7) |
1 (50) |
| Ring-billed Gulld |
2 |
NT |
3.1 (2.0–3.3) |
2.8 (1.8–3.0) |
3.3 (2.6–3.6) |
3.5 |
3.5 |
3.4 |
2 (100) |
| Mourning Dove |
3 |
NT |
<–0.2 |
0.8 (<0.4–1.2) |
0.5 (<0.4–0.8) |
0.5 (<0.4–0.8) |
<–0.2 |
<–0.2 |
2 (67) |
| Monk Parakeet |
3 |
<–0.2 |
<–0.2 |
<–0.2 |
<–0.2 |
<–0.2 |
<–0.2 |
<–0.2 |
0 (0) |
| Budgerigar |
3 |
NT |
<–0.2 |
<–0.2 |
<–0.2 |
<–0.2 |
<–0.2 |
<–0.2 |
0 (0) |
| Great Horned Owl |
1 |
<0.4 |
1.3 |
3.1 |
<0.4 |
5.8 |
4.9 |
2.8 |
1 (100) |
| Northern Flicker |
1 |
<0.4 |
<0.4 |
<0.4 |
<0.4 |
<0.4 |
<0.4 |
<0.4 |
0 (0) |
| Blue Jaye |
2 |
0.9 (<0.4–1.2) |
4.0 (1.4–4.3) |
3.9 (2.5–4.2) |
3.6 |
3.7 |
2.2 |
1.2 |
2 (100) |
| Black-billed Magpie |
3 |
<–0.2 |
0.8 (<0.4–1.0) |
2.1 (1.4–2.5) |
3.1 (2.5–3.3) |
4.0 (<0.4–4.4) |
– |
– |
3 (100) |
| American Crow |
6 |
<–0.5 |
2.3 (<0.4–2.5) |
5.0 (1.6–5.5) |
4.3 (3.1–4.7) |
5.7 |
– |
– |
6 (100) |
| Fish Crowf | 8 | <–0.6 | 1.0 (<0.4–1.7) | 3.4 (1.3–4.2) | 3.6 (<0.4–4.1) | 3.8 (1.8–4.4) | 3.8 (1.6–4.6) | 3.5 (1.9–4.1) | 8 (100) |
aPresented as mean log10 PFU/swab, with ranges.
bNT, not tested; –, no birds survived the infection to be sampled.
cAmerican Kestrels were tested at 9, 10,and 11 days postinoculation, with the following results for days 9 and10, respectively: 2.3 (1.8–2.5); 1.8 (<0.4–2.1). WNV was not isolated from oral swabs collected on day 11.
dThis Ring-billed Gull developed signs of illness after 7 days postinoculation and was euthanized at 13 days postinoculation, at which time an oral swab contained 10 PFU WNV.
eThis Blue Jay was sampled at 8 and 9 days postinoculation. No virus was isolated from oral swabs.
fSurviving Fish Crows were tested at 8 and 9 days postinoculation with the following results for days 8 and 9, respectively: 3.6 (2.0–4.3); 2.1 (<–0.5–2.5).