Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2007
Year To Date (Weeks 1 - 46)

(2022-11-29) - Source: http://westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda1065220199%
Alpine62--
Amador1123113%
Butte10451212722%
Calaveras2083738%
Colusa5012433%
Contra Costa20422942810%
Del Norte4611--
El Dorado44110077%
Fresno201028411340%
Glenn158633657%
Humboldt1474225%
Imperial112--
Inyo475120%
Kern188830812440%
Kings19134926%
Lake14521314%
Lassen842428%
Los Angeles251862716126%
Madera15833618%
Marin4556646%
Mariposa499--
Mendocino11524313%
Merced484903438%
Modoc197114%
Mono604--
Monterey34949--
Napa1396233%
Nevada3268356%
Orange8331913217%
Placer1002931617%
Plumas812414%
Riverside64939615%
Sacramento598535914240%
San Benito5620--
San Bernardino7951532617%
San Diego87429810636%
San Francisco1613513%
San Joaquin1581894652%
San Luis Obispo32273912%
San Mateo58514321%
Santa Barbara2082514%
Santa Clara19982608332%
Santa Cruz3578267%
Shasta8081314736%
Sierra134--
Siskiyou348450%
Solano60219316%
Sonoma8491521913%
Stanislaus146524313053%
Sutter2556117%
Tehama199532038%
Trinity601318%
Tulare5721293729%
Tuolumne1463213%
Ventura6281521510%
Yolo6481382518%
Yuba1208113%
State Totals362545581137625%

* 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