Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2018
Year To Date (Weeks 1 - 53)

(2019-04-23) - Source: http://www.westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda344802025%
Alpine----
Amador161--
Butte10230413%
Calaveras8---
Colusa71--
Contra Costa711451329%
Del Norte31--
El Dorado942229%
Fresno1624--
Glenn6---
Humboldt245120%
Imperial1---
Inyo2---
Kern433133%
Kings142--
Lake217--
Lassen----
Los Angeles839921921%
Madera132--
Marin591--
Mariposa----
Mendocino10---
Merced551--
Modoc----
Mono----
Monterey344--
Napa194--
Nevada265--
Orange518389185%
Placer4652144421%
Plumas2---
Riverside16632619%
Sacramento154255424144%
San Benito91--
San Bernardino15420--
San Diego1869011%
San Francisco563--
San Joaquin208421638%
San Luis Obispo236--
San Mateo40912754%
Santa Barbara346--
Santa Clara7002375624%
Santa Cruz1324624%
Shasta379556%
Sierra1---
Siskiyou1---
Solano13415--
Sonoma11313--
Stanislaus1518113%
Sutter7624417%
Tehama184--
Trinity2---
Tulare6110--
Tuolumne132150%
Ventura9715--
Yolo253924145%
Yuba4217--
State Totals8216228650122%

* 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