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-
Riverside1
Sacramento-
San Benito-
San Bernardino-
San Diego22
San Francisco-
San Joaquin-
San Luis Obispo-
San Mateo2
Santa Barbara-
Santa Clara10
Santa Cruz-
Shasta-
Sierra-
Siskiyou-
Solano-
Sonoma2
Stanislaus1
Sutter-
Tehama-
Trinity-
Tulare-
Tuolumne-
Ventura-
Yolo-
Yuba-
Total39

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.

Interactive Map

View the interactive map courtesy of http://maps.calsurv.org
- View Printable Map -

Total Counties with
WNV in 2015: 10

Alameda, Los Angeles, Riverside, San Diego, San Mateo, Santa Barbara, Santa Clara, Sonoma, Stanislaus, and Tulare.

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 -

human cases

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

dead birds

YTD: 39 Counties: 7
There were 21 new WNV positive dead birds reported in California last week from the following counties: Riverside (1), San Diego (16), and Santa Clara (4). This is the first WNV positive dead bird from Riverside County this year.

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

 

mosquito samples

YTD: 25 Counties: 5
There were 8 new WNV positive mosquito samples reported in California last week from the following counties: Los Angeles (1), Riverside (4), and Tulare (3).

25 mosquito samples from 5 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 May 22, 2015201520145Y AVG
Counties1096
Human cases000
Dead birds39199
Mosquito samples2573
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

05.22 Arbovirus Bulletin #12
05.22 2015 YTD WNV Activity Map
05.15 Arbovirus Bulletin #11

Humans

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

Dead Birds

05.22Positive Species for 2015
05.22Positive Counts by City/County for 2015
05.22Reported, Tested, Positive 2015

Mosquitoes

05.22 AMOR - EVS Week 19
05.22 AMOR - GRAVID Week 19
05.22 AMOR - NJLT Week 19
- view report archives -