Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2016
Year To Date (Weeks 1 - 53)

(2024-10-13) - Source: http://westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda323511122%
Alpine----
Amador10---
Butte185432251%
Calaveras25---
Colusa51--
Contra Costa861753344%
Del Norte----
El Dorado10816425%
Fresno2148675%
Glenn156467%
Humboldt19---
Imperial1---
Inyo2---
Kern631--
Kings226467%
Lake5816531%
Lassen----
Los Angeles110218812466%
Madera279556%
Marin10610550%
Mariposa6---
Mendocino20---
Merced769556%
Modoc6---
Mono2---
Monterey461--
Napa423133%
Nevada4110220%
Orange6824079122%
Placer3081903016%
Plumas----
Riverside157411639%
Sacramento177370141159%
San Benito51--
San Bernardino10927519%
San Diego73736726472%
San Francisco528--
San Joaquin317703753%
San Luis Obispo315--
San Mateo5291111514%
Santa Barbara413--
Santa Clara8821638955%
Santa Cruz1252628%
Shasta534375%
Sierra----
Siskiyou5---
Solano144301343%
Sonoma17524833%
Stanislaus299261454%
Sutter79241042%
Tehama28---
Trinity1---
Tulare7616319%
Tuolumne2---
Ventura230463474%
Yolo3671297256%
Yuba407457%
State Totals106322879135247%

* 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