Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2022
Year To Date (Weeks 1 - 20)

(2022-05-22) - Source: http://westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda61---
Alpine----
Amador2---
Butte10---
Calaveras1---
Colusa2---
Contra Costa1116117%
Del Norte----
El Dorado82--
Fresno31---
Glenn2---
Humboldt----
Imperial----
Inyo----
Kern9---
Kings5---
Lake----
Lassen----
Los Angeles21617--
Madera31--
Marin111--
Mariposa----
Mendocino----
Merced13---
Modoc----
Mono----
Monterey41--
Napa2---
Nevada6---
Orange143107--
Placer26---
Plumas----
Riverside20---
Sacramento16849--
San Benito1---
San Bernardino216--
San Diego4516--
San Francisco5---
San Joaquin4510--
San Luis Obispo9---
San Mateo514--
Santa Barbara7---
Santa Clara12618--
Santa Cruz183--
Shasta121--
Sierra----
Siskiyou1---
Solano342--
Sonoma214--
Stanislaus46---
Sutter83--
Tehama1---
Trinity----
Tulare115--
Tuolumne2---
Ventura17---
Yolo297--
Yuba1---
State Totals136526310%

* 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