Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2007
Year To Date (Weeks 1 - 53)

(2021-12-01) - Source: http://westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda1065245198%
Alpine62--
Amador1123113%
Butte10451242722%
Calaveras2083938%
Colusa5012433%
Contra Costa2042314289%
Del Norte4611--
El Dorado44110777%
Fresno201029411439%
Glenn158653655%
Humboldt1474624%
Imperial112--
Inyo475120%
Kern188833312437%
Kings19136925%
Lake14522314%
Lassen842528%
Los Angeles251867616524%
Madera15835617%
Marin4557146%
Mariposa499--
Mendocino11527311%
Merced484973435%
Modoc197114%
Mono604--
Monterey34957--
Napa1398225%
Nevada3268656%
Orange8332384318%
Placer1002981616%
Plumas812514%
Riverside64941615%
Sacramento598538114237%
San Benito5624--
San Bernardino7951612616%
San Diego87432810833%
San Francisco1614013%
San Joaquin1581964648%
San Luis Obispo32284911%
San Mateo58515021%
Santa Barbara2083013%
Santa Clara19982758330%
Santa Cruz3578567%
Shasta8081354836%
Sierra134--
Siskiyou349444%
Solano60219316%
Sonoma8491591912%
Stanislaus146526213050%
Sutter2556117%
Tehama199532038%
Trinity601417%
Tulare5721363828%
Tuolumne1463613%
Ventura628171159%
Yolo6481402518%
Yuba1208113%
State Totals362545998139623%

* Birds in a die-off are not included in reported totals because the deaths are not related to WNV. A die-off is defined as a group of 10 or more same species dead birds unless the species is American Crow.
Source: Vector-Borne Disease Section, California Department of Public Health