Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2024
Year To Date (Weeks 1 - 28)

(2024-07-15) - Source: http://westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda257161381%
Alpine----
Amador3---
Butte238113%
Calaveras3---
Colusa----
Contra Costa2323439%
Del Norte1---
El Dorado375--
Fresno60---
Glenn1---
Humboldt52--
Imperial1---
Inyo1---
Kern101--
Kings6---
Lake145--
Lassen3---
Los Angeles4516612%
Madera8---
Marin311--
Mariposa1---
Mendocino2---
Merced204--
Modoc----
Mono1---
Monterey16---
Napa143--
Nevada142--
Orange16242--
Placer12951--
Plumas1---
Riverside792215%
Sacramento4452002915%
San Benito2---
San Bernardino6121314%
San Diego1365724%
San Francisco322--
San Joaquin8122314%
San Luis Obispo193--
San Mateo2386569%
Santa Barbara213--
Santa Clara3601243831%
Santa Cruz374--
Shasta111--
Sierra----
Siskiyou----
Solano6322--
Sonoma687--
Stanislaus734--
Sutter254--
Tehama2---
Trinity----
Tulare2210--
Tuolumne1---
Ventura507--
Yolo1053813%
Yuba10---
State Totals344885610112%

* 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