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 Diego3
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-
Total7

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

Data on this website is updated every Friday 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: 5

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

California Sets Record for West Nile Virus Activity
SACRAMENTO - It was a record-breaking year for West Nile virus activity in 2014 California Department of Public Health (CDPH) Director and State Health Officer Dr. Karen Smith announced today.
- view news and press release archives -

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: 7 Counties: 3
There were 2 new WNV positive dead birds reported in California this week from San Diego County.

7 dead birds from 3 counties have tested positive for WNV in 2015.

 

mosquito samples

YTD: 2 Counties: 2
There was 1 new WNV positive mosquito sample reported in California this week from Santa Barbara County. This is the first indication of WNV from Santa Barbara County this year.

2 mosquito samples from 2 counties have 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) 801 (31) 4,805 (176)
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 Apr 17, 2015201520145Y AVG
Counties563
Human cases041
Dead birds7134
Mosquito samples200
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

04.17 Arbovirus Bulletin #7
04.17 2015 YTD WNV Activity Map
04.10 Arbovirus Bulletin #6

Humans

04.02 2003-2014 WNV Case Summary
03.09 2014 Human WNV Incidence Report
08.12 2013 Human WNV Incidence Report

Dead Birds

04.17Positive Species for 2015
04.17Positive Counts by City/County for 2015
04.17Reported, Tested, Positive 2015

Mosquitoes

04.17 AMOR - EVS Week 14
04.17 AMOR - GRAVID Week 14
04.17 AMOR - NJLT Week 14
- view report archives -