Case Counts by County

CountyDead birds
Alameda1
Alpine-
Amador-
Butte-
Calaveras-
Colusa-
Contra Costa-
Del Norte-
El Dorado-
Fresno-
Glenn-
Humboldt-
Imperial-
Inyo-
Kern-
Kings-
Lake-
Lassen-
Los Angeles-
Madera-
Marin-
Mariposa-
Mendocino-
Merced-
Modoc-
Mono-
Monterey-
Napa-
Nevada-
Orange-
Placer-
Plumas-
Riverside-
Sacramento-
San Benito-
San Bernardino-
San Diego-
San Francisco-
San Joaquin-
San Luis Obispo-
San Mateo-
Santa Barbara-
Santa Clara3
Santa Cruz-
Shasta-
Sierra-
Siskiyou-
Solano-
Sonoma-
Stanislaus-
Sutter-
Tehama-
Trinity-
Tulare-
Tuolumne-
Ventura-
Yolo-
Yuba-
Total4

WNV Activity by County
Printable Version
2015 | 2014 | 2013
2012 | 2011 | 2010
2009 | 2008 | 2007

Human data is updated every Tuesday by 4pm. Dead bird data is updated every Wednesday and Friday by 4pm. Mosquito and sentinel chicken data are updated on Fridays by 4pm.

Due to different reporting schedules, case totals on this website may not always be consistent with those reported by local health departments.
- View Printable Map -

Total Counties with
WNV in 2015: 3

New counties highlighted in red.
Alameda, Los Angeles, and Santa Clara.

Click for 2014 WNV Activity

human cases

YTD: 0 Counties: 0
No cases of human WNV illness have been reported positive for WNV in 2015.
 

dead birds

YTD: 4 Counties: 2
There were 3 new WNV positive dead birds reported in California this week from Santa Clara County. This is the first indication of WNV from Santa Clara County this year.

4 dead birds from 2 counties have tested positive for WNV in 2015.

 

mosquito samples

YTD: 1 Counties: 1
There was 1 new WNV positive mosquito sample reported in California this week from Los Angeles County. This is the first indication of WNV from Los Angeles County this year.

1 mosquito sample from 1 county has tested positive for WNV in 2015.

 

sentinel chickens

YTD: 0 Counties: 0
No sentinel chickens have tested positive for WNV in 2015.

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2003-2014 WNV Activity Summary

Element 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Total
Human cases (fatal) 31 (0) 779 (29) 880 (19) 278 (7) 380 (21) 445 (15) 112 (4) 111 (6) 158 (9) 479 (20) 379 (15) 798 (29) 4,802 (174)
Horses 12 540 456 58 28 32 18 19 15 22 13 03 1,202
Dead birds 96 3,232 3,046 1,446 1,396 2,569 515 416 688 1,644 1,251 2,442 18,741
Mosquito samples 32 1,136 1,242 832 1,007 2,003 1,063 1,305 2,087 2849 2,528 3,340 19,424
Sentinel chickens 70 809 1,053 640 510 585 443 281 391 540 485 443 6,250
Squirrels - 49 48 32 26 32 10 24 24 23 03 03 276
1 There were 20 imported human cases. 2 There were 3 imported horse cases. 3 No longer monitored.

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Compared to previous year and previous five-year average to date

As of Mar 26, 2015201520145Y AVG
Counties332
Human cases000
Dead birds473
Mosquito samples100
Sentinel chickens010
YTD - Year to date corresponds to the same time last year or last five years.

- view all 2014 YTD activity -

WNV Reports

Weekly Report

03.27 Arbovirus Bulletin #4
03.27 2015 YTD WNV Activity Map
03.20 Arbovirus Bulletin #3

Humans

01.29 2003-2014 WNV Case Summary
01.12 2014 Human WNV Incidence Report
08.12 2013 Human WNV Incidence Report

Dead Birds

03.27Positive Species for 2015
03.27Positive Counts by City/County for 2015
03.27Reported, Tested, Positive 2015

Mosquitoes

11.07 AMOR - EVS Week 44
11.07 AMOR - GRAVID Week 44
11.07 AMOR - NJLT Week 44
- view report archives -