Dead Birds Reported, Tested, and Positive
for WNV by County in California in 2017
Year To Date (Weeks 1 - 33)

(2017-08-21) - Source: http://www.westnile.ca.gov

CountyReported*TestedPositive% Tested Positive
Alameda1883313%
Alpine1---
Amador10---
Butte4916213%
Calaveras7---
Colusa82150%
Contra Costa41720525%
Del Norte----
El Dorado551119%
Fresno1206233%
Glenn3---
Humboldt7---
Imperial1---
Inyo5---
Kern6833100%
Kings263133%
Lake281616%
Lassen----
Los Angeles548783241%
Madera202--
Marin427--
Mariposa2---
Mendocino8---
Merced415120%
Modoc----
Mono2---
Monterey204125%
Napa253--
Nevada185120%
Orange441287186%
Placer20910311%
Plumas1---
Riverside192462350%
Sacramento7232724015%
San Benito81--
San Bernardino170392769%
San Diego156551425%
San Francisco335--
San Joaquin18638616%
San Luis Obispo122--
San Mateo2755212%
Santa Barbara195--
Santa Clara33450510%
Santa Cruz561318%
Shasta23---
Sierra1---
Siskiyou1---
Solano671318%
Sonoma9320--
Stanislaus15714321%
Sutter431517%
Tehama9---
Trinity1---
Tulare6016850%
Tuolumne21--
Ventura8213--
Yolo1093813%
Yuba3212433%
State Totals5214132420616%

* 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