Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2018
Year To Date (Weeks 1 - 37)

(2018-09-21) - Source: http://www.westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda269321650%
Alpine----
Amador151--
Butte8726312%
Calaveras7---
Colusa71--
Contra Costa575401230%
Del Norte31--
El Dorado7821210%
Fresno1471--
Glenn6---
Humboldt234125%
Imperial1---
Inyo2---
Kern391--
Kings122--
Lake185--
Lassen----
Los Angeles669601017%
Madera122--
Marin391--
Mariposa----
Mendocino6---
Merced511--
Modoc----
Mono----
Monterey303--
Napa172--
Nevada224--
Orange33725062%
Placer3941644125%
Plumas2---
Riverside13525520%
Sacramento132052823444%
San Benito71--
San Bernardino12914--
San Diego13760--
San Francisco382--
San Joaquin173311135%
San Luis Obispo175--
San Mateo3209155%
Santa Barbara223--
Santa Clara5571724727%
Santa Cruz1103626%
Shasta277457%
Sierra1---
Siskiyou----
Solano10512--
Sonoma898--
Stanislaus1367114%
Sutter6418422%
Tehama134--
Trinity2---
Tulare519--
Tuolumne5---
Ventura8315--
Yolo200813948%
Yuba4017--
State Totals6649176844325%

* 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