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

County	Reported*	Tested	Positive	% Tested Positive
Alameda	516	77	22	29%
Alpine	3	-	-	-
Amador	23	1	-	-
Butte	390	82	42	51%
Calaveras	23	1	-	-
Colusa	24	2	1	50%
Contra Costa	1397	123	68	55%
Del Norte	-	-	-	-
El Dorado	145	25	-	-
Fresno	414	67	12	18%
Glenn	23	10	8	80%
Humboldt	26	3	1	33%
Imperial	2	-	-	-
Inyo	8	1	-	-
Kern	157	21	2	10%
Kings	97	22	12	55%
Lake	117	24	10	42%
Lassen	2	-	-	-
Los Angeles	2997	522	313	60%
Madera	65	13	7	54%
Marin	271	33	7	21%
Mariposa	7	2	-	-
Mendocino	34	4	2	50%
Merced	303	60	39	65%
Modoc	4	-	-	-
Mono	6	1	-	-
Monterey	67	14	-	-
Napa	93	4	2	50%
Nevada	86	17	6	35%
Orange	601	318	42	13%
Placer	436	186	39	21%
Plumas	7	-	-	-
Riverside	468	42	22	52%
Sacramento	1538	460	179	39%
San Benito	27	3	-	-
San Bernardino	480	100	37	37%
San Diego	240	107	9	8%
San Francisco	72	7	-	-
San Joaquin	426	91	34	37%
San Luis Obispo	81	17	1	6%
San Mateo	318	62	-	-
Santa Barbara	47	9	-	-
Santa Clara	1112	234	77	33%
Santa Cruz	170	19	1	5%
Shasta	218	73	38	52%
Sierra	1	-	-	-
Siskiyou	1	-	-	-
Solano	339	26	15	58%
Sonoma	499	74	37	50%
Stanislaus	383	38	13	34%
Sutter	175	33	16	48%
Tehama	37	7	3	43%
Trinity	6	1	1	100%
Tulare	168	35	7	20%
Tuolumne	14	3	1	33%
Ventura	234	38	8	21%
Yolo	473	175	106	61%
Yuba	91	20	11	55%
State Totals	15962	3307	1251	38%

^* 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