Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2013
Year To Date (Weeks 1 - 53)

(2017-05-29) - Source: http://www.westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda516772229%
Alpine3---
Amador231--
Butte390824251%
Calaveras231--
Colusa242150%
Contra Costa13971236855%
Del Norte----
El Dorado14525--
Fresno414671218%
Glenn2310880%
Humboldt263133%
Imperial2---
Inyo81--
Kern15721210%
Kings97221255%
Lake117241042%
Lassen2---
Los Angeles299752231360%
Madera6513754%
Marin27133721%
Mariposa72--
Mendocino344250%
Merced303603965%
Modoc4---
Mono61--
Monterey6714--
Napa934250%
Nevada8617635%
Orange6013184213%
Placer4361863921%
Plumas7---
Riverside468422252%
Sacramento153846017939%
San Benito273--
San Bernardino4801003737%
San Diego24010798%
San Francisco727--
San Joaquin426913437%
San Luis Obispo811716%
San Mateo31862--
Santa Barbara479--
Santa Clara11122347733%
Santa Cruz1701915%
Shasta218733852%
Sierra1---
Siskiyou1---
Solano339261558%
Sonoma499743750%
Stanislaus383381334%
Sutter175331648%
Tehama377343%
Trinity611100%
Tulare16835720%
Tuolumne143133%
Ventura23438821%
Yolo47317510661%
Yuba91201155%
State Totals159623307125138%

* 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