Volume 7, Number 4—August 2001
THEME ISSUE
West Nile Virus
West Nile Virus
Dead Bird Surveillance as an Early Warning System for West Nile Virus
Table
No. pos. on WN virus testing |
No. neg. on WN virus testing |
|||
---|---|---|---|---|
Species | No. pos. on necropsy (%)b | No. neg. on necropsy | No. pos. on necropsy | No. neg. on necropsy (%)c |
Jan 1 - Jul 19 | ||||
American Crowd | 29 (51.8) | 27 | 34 | 551 (94.2) |
Blue Jay | 7 (25) | 21 | 37 | 101 (73.2) |
Fish Crow | 0 (--) | 2 | 1 | 18 (94.7) |
American Robin | 0 (--) | 0 | 5 | 18 (78.3) |
House Sparrow | 0 (--) | 1 | 2 | 35 (94.6) |
Other species | 2 (25) | 6 | 19 | 186 (90.7) |
Totale | 38 (40) | 57 | 98 | 909 (90.3) |
(PPV=27.9%) | (NPV=85.3%) | |||
Jul 20 - Dec 31 | ||||
American Crowd | 624 (79.0) | 166 | 303 | 269 (47.0) |
Blue Jay | 76 (61.3) | 48 | 124 | 126 (50.4) |
Fish Crow | 16 (84.2) | 3 | 10 | 3 (23.1) |
American Robin | 7 (43.8) | 9 | 32 | 16 (33.3) |
House Sparrow | 3 (18.8) | 13 | 11 | 32 (74.4) |
Other species | 68 (33.5) | 135 | 166 | 614 (78.7) |
Totale | 794 (68.0) | 374 | 646 | 1,060 (62.1) |
(PPV=55.1%) |
(NPV=73.9%) |
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Total (all year) | 832 (65.8%) | 431 | 744 | 1,969 (72.6%) |
aGross postmortem signs considered indicative of possible WN virus infection included one or more of the following: emaciation, splenomegaly, hepatomegaly, cardiac or pericardial lesions, and possible signs of encephalitis.
bSensitivity of pathologic findings on gross necropsy for detecting WN virus.
cSpecificity of pathologic findings on gross necropsy for ruling out WN virus.
dDifferences between American Crows and other species combined significant at 0.05 level.
eDifferences between time periods (all species combined) significant at 0.001 level.
1Bryon Backenson, Kristen Bernard, Hwa-Gan Chang, Alan Dupuis, Gregory Ebel, Ivan Gotham, Susan Jones, Elizabeth Kauffman, Dale Morse, John Napoli, Perry Smith, Charles Trimarchi, Barbara Wallace, Dennis White, Amy Willsey, New York State Department of Health