Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2019
Year To Date (Weeks 1 - 53)

(2020-01-21) - Source: http://www.westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda21383--
Alpine----
Amador4---
Butte672115%
Calaveras8---
Colusa71--
Contra Costa3212314%
Del Norte----
El Dorado4714--
Fresno344161063%
Glenn3---
Humboldt84--
Imperial1---
Inyo14---
Kern2722100%
Kings15---
Lake122--
Lassen2---
Los Angeles6941785330%
Madera9---
Marin535--
Mariposa1---
Mendocino7---
Merced405360%
Modoc----
Mono1---
Monterey214--
Napa251--
Nevada43--
Orange6164895010%
Placer18411833%
Plumas2---
Riverside11638513%
Sacramento7383174414%
San Benito31--
San Bernardino10520420%
San Diego17511622%
San Francisco475--
San Joaquin13733515%
San Luis Obispo296--
San Mateo23361--
Santa Barbara222--
Santa Clara44215085%
Santa Cruz9422--
Shasta1911100%
Sierra----
Siskiyou1---
Solano5511--
Sonoma546--
Stanislaus14214429%
Sutter4910--
Tehama6---
Trinity----
Tulare135311755%
Tuolumne152150%
Ventura9216213%
Yolo18167710%
Yuba369333%
State Totals5676190722612%

* 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