Volume 10, Number 12—December 2004
Dispatch
Detecting West Nile Virus in Owls and Raptors by an Antigen-capture Assay
Table
RT-PCR results and sensitivity of the VecTest assay in 19 species of North American owls and raptors tested for West Nile virusa
RT-PCR |
VecTest |
|||||||
---|---|---|---|---|---|---|---|---|
OP swab |
Cloacal swab |
Combinedb |
||||||
Species | N | No. positive | N | Sn (%) | N | Sn (%) | N | Sn (%) |
Great Gray Owl (Strix nebulosa)c | 19 | 17 | 19 | 100.0 | 19 | 100.0 | 19 | 100.0 |
Northern Hawk Owl (Surnia ulula)c | 16 | 16 | 16 | 100.0 | 15 | 93.3 | 15 | 100.0 |
Boreal Owl (Aegolius funereus)c | 13 | 10 | 13 | 80.0 | 13 | 90.0 | 13 | 90.0 |
Northern Saw-whet Owl (Aegolius acadicus)c | 12 | 10 | 12 | 100.0 | 12 | 100.0 | 12 | 100.0 |
Snowy Owl (Bubo scandiacus)c | 9 | 9 | 9 | 88.9 | 9 | 77.8 | 9 | 88.9 |
Great Horned Owl (Bubo virginianus) | 10 | 8 | 10 | 62.5 | 4 | 50.0 | 4 | 50.0 |
Short-eared Owl (Asio flammeus) | 3 | 2 | 3 | 50.0 | 3 | 50.0 | 3 | 50.0 |
Long-eared Owls (Asio otus) | 3 | 1 | 3 | 100.0 | 3 | 100.0 | 3 | 100.0 |
Barred Owl (Strix varia) | 2 | 0 | 2 | – | 2 | – | 2 | – |
Northern Pygmy-Owl (Glaucidium gnoma) | 1 | 1 | 1 | 0.0 | 1 | 0.0 | 1 | 0.0 |
Flammulated Owl (Otus flammeolus) | 1 | 1 | 1 | 0.0 | 1 | 0.0 | 1 | 0.0 |
Tawny Owl (Strix aluco) | 1 | 1 | 1 | 0.0 | 1 | 100 | 1 | 100 |
Eastern Screech-Owl (Megascops asio) | 2 | 0 | 2 | – | 2 | – | 2 | – |
Spotted Owl (Strix occidentalis) | 1 | 0 | 1 | – | 1 | – | 1 | – |
American Kestrel (Falco sparverius) | 1 | 0 | 1 | – | 1 | – | 1 | – |
Red-tailed Hawk (Buteo jamaicensis) | 19 | 11 | 19 | 36.4 | 0 | –- | 0 | – |
Cooper’s Hawk (Accipiter cooperii) | 2 | 1 | 2 | 0.0 | 0 | – | 0 | – |
Sharp-shinned Hawk (Accipiter striatus) | 4 | 1 | 4 | 100.0 | 0 | – | 0 | – |
Osprey (Pandion haliaetus) | 1 | 0 | 1 | – | 0 | – | 0 | – |
Total | 120 | 89 | 120 | 77.5 | 86 | 88.4 | 86 | 91.4 |
aRT-PCR, real-time reverse transcription–polymerase chain reaction; OP, oropharyngeal; N, sample size; Sn, sensitivity.
bResults of oropharyngeal and cloacal swab testing were considered in parallel (i.e., the bird was considered positive if one of the two tests was positive).
cNorthern owl species.