Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2007
Year To Date (Weeks 1 - 48)

(2021-12-06) - Source: http://westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda1065234198%
Alpine62--
Amador1123113%
Butte10451212722%
Calaveras2083738%
Colusa5012433%
Contra Costa2042298289%
Del Norte4611--
El Dorado44110277%
Fresno201028711440%
Glenn158643656%
Humboldt1474325%
Imperial112--
Inyo475120%
Kern188831412439%
Kings19136925%
Lake14522314%
Lassen842428%
Los Angeles251864716325%
Madera15835617%
Marin4556746%
Mariposa499--
Mendocino11524313%
Merced484943436%
Modoc197114%
Mono604--
Monterey34957--
Napa1398225%
Nevada3268556%
Orange8332074120%
Placer1002951617%
Plumas812514%
Riverside64939615%
Sacramento598536914238%
San Benito5623--
San Bernardino7951582616%
San Diego87431610834%
San Francisco1613813%
San Joaquin1581894652%
San Luis Obispo32278912%
San Mateo58514521%
Santa Barbara2082814%
Santa Clara19982658331%
Santa Cruz3578467%
Shasta8081334836%
Sierra134--
Siskiyou349444%
Solano60219316%
Sonoma8491561912%
Stanislaus146524913052%
Sutter2556117%
Tehama199532038%
Trinity601318%
Tulare5721313829%
Tuolumne1463413%
Ventura628160159%
Yolo6481402518%
Yuba1208113%
State Totals362545756139224%

* 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