Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2017
Year To Date (Weeks 1 - 53)

(2018-07-22) - Source: http://www.westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda2763925%
Alpine1---
Amador11---
Butte9824521%
Calaveras8---
Colusa102150%
Contra Costa695431944%
Del Norte----
El Dorado7218211%
Fresno16811545%
Glenn622100%
Humboldt122150%
Imperial3---
Inyo12---
Kern7633100%
Kings283133%
Lake4025520%
Lassen----
Los Angeles88916010163%
Madera273133%
Marin649111%
Mariposa4---
Mendocino11---
Merced647114%
Modoc----
Mono2---
Monterey344125%
Napa395--
Nevada258113%
Orange6744755712%
Placer25012443%
Plumas1---
Riverside289684160%
Sacramento9453588624%
San Benito91--
San Bernardino258594576%
San Diego2461064341%
San Francisco551119%
San Joaquin23340718%
San Luis Obispo5913646%
San Mateo4047911%
Santa Barbara376117%
Santa Clara5151031515%
Santa Cruz801816%
Shasta473267%
Sierra1---
Siskiyou1---
Solano10421419%
Sonoma13026519%
Stanislaus21722627%
Sutter5822314%
Tehama9---
Trinity11--
Tulare8216850%
Tuolumne71--
Ventura11916213%
Yolo195611423%
Yuba4416638%
State Totals7745203451025%

* 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