Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2012
Year To Date (Weeks 1 - 53)

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

CountyReported*TestedPositive% Tested Positive
Alameda5911181513%
Alpine22--
Amador37---
Butte5301115348%
Calaveras432--
Colusa528563%
Contra Costa18211066662%
Del Norte----
El Dorado3879955%
Fresno410602542%
Glenn57281657%
Humboldt114--
Imperial4---
Inyo7---
Kern367581424%
Kings7413215%
Lake97221045%
Lassen6---
Los Angeles359155727149%
Madera5813215%
Marin19210110%
Mariposa71--
Mendocino6612650%
Merced391604270%
Modoc74--
Mono2---
Monterey12529--
Napa829111%
Nevada7916319%
Orange7703499026%
Placer6163206019%
Plumas13---
Riverside35132516%
Sacramento368796046649%
San Benito204--
San Bernardino6521203933%
San Diego25911222%
San Francisco1181915%
San Joaquin8991455840%
San Luis Obispo1311616%
San Mateo4125459%
Santa Barbara7113--
Santa Clara8681642012%
Santa Cruz1853913%
Shasta284693652%
Sierra21--
Siskiyou102--
Solano563492857%
Sonoma40055815%
Stanislaus7921125146%
Sutter167432967%
Tehama11311545%
Trinity4---
Tulare3871105449%
Tuolumne201--
Ventura4941033837%
Yolo6022019849%
Yuba150181161%
State Totals221364464164337%

* 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