Case Counts by County

CountyDead birds
Alameda-
Alpine-
Amador-
Butte-
Calaveras-
Colusa-
Contra Costa-
Del Norte-
El Dorado-
Fresno-
Glenn-
Humboldt-
Imperial-
Inyo-
Kern-
Kings-
Lake-
Lassen-
Los Angeles1
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 Clara-
Santa Cruz-
Shasta-
Sierra-
Siskiyou-
Solano-
Sonoma-
Stanislaus-
Sutter-
Tehama-
Trinity-
Tulare-
Tuolumne-
Ventura-
Yolo-
Yuba1
Total2

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

Human data is updated every Tuesday and Friday by 4pm. Dead bird and squirrel data are updated every Wednesday and Friday by 4pm. Horse, mosquito and sentinel chicken data are updated on Fridays by 4pm.
- View Printable Map -

Total Counties with
WNV in 2013: 5

New counties highlighted in red.
Fresno, Los Angeles, San Joaquin, Tulare, and Yuba.

Climate Change May Mean More Mosquitoes -- And Diseases
[via The California Report] It's mosquito season, and that means that West Nile virus is back. The Midwest outbreak this summer is the worst in U.S. history, with 50 deaths so far in Texas alone. Fewer people have gotten sick in California, but the disease showed up here earlier than usual. And scientists are concerned that as the climate warms, West Nile and other mosquito-borne illnesses will gain a stronger foothold here. Reporter: Molly Samuel
Reporting a Dead Bird Video
- 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 2013.
 

horses

YTD: 0 Counties: 0
No horses have tested positive for WNV in 2013.
 

dead birds

YTD: 2 Counties: 2

For more information about WNV positive and chronic dead birds, click here.

2 dead birds from 2 counties have tested positive for WNV in 2013.

 

mosquito samples

YTD: 9 Counties: 4
There were 7 new WNV positive mosquito samples reported in California this week from the following counties: Fresno (1), Los Angeles (3), San Joaquin (2), and Tulare (1). This is the first WNV positive mosquito sample from Los Angeles County this year. This is the first indication of WNV from San Joaquin County this year. 9 mosquito samples from 4 counties have tested positive for WNV in 2013.
 

sentinel chickens

YTD: 0 Counties: 0
No sentinel chickens have tested positive for WNV in 2013.
 

squirrels

YTD: 0 Counties: 0
No squirrels have tested positive for WNV in 2013.

Be a West Nile Watcher

Help us track down the West Nile Virus by reporting all dead birds and squirrels. Call 1-877-968-2473 to report a dead bird or squirrel or you can submit an online report.

2003-2012 WNV Activity Summary

Element 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Total
Human cases (fatal) 31 (0) 779 (29) 880 (19) 278 (7) 380 (21) 445 (15) 112 (4) 111 (6) 158 (9) 479 (20) 3,625 (130)
Horses 12 540 456 58 28 32 18 19 15 22 1,189
Dead birds 96 3,232 3,046 1,446 1,396 2,569 515 416 688 1,644 15,048
Mosquito samples 32 1,136 1,242 832 1,007 2,003 1063 1305 2087 2,849 13,556
Sentinel chickens 70 809 1,053 640 510 585 443 281 391 540 5,322
Squirrels - 49 48 32 26 32 10 24 24 23 268
1 There were 20 imported human cases. 2 There were 3 imported horse cases.

Locate Your Local Mosquito and Vector Control Agency
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Compared to 2012 YTD

As of May 24, 201320122013
Counties95
Human cases00
Horses00
Dead birds162
Mosquito samples89
Sentinel chickens00
Squirrels00
2012 YTD - Year to date corresponds to the same time last year.

- view all 2012 YTD activity -

WNV Reports

Weekly Report

05.24 Arbovirus Bulletin #12
05.24 2013 YTD WNV Activity Map
05.20 Arbovirus Bulletin #11

Humans

04.26 2012 Human WNV Case Linelist
04.26 2003-2012 WNV Case Summary
03.18 2012 Human WNV Incidence Report

Dead Birds

05.24Positive Species for 2013
05.24Positive Counts by City/County for 2013
05.24Reported, Tested, Positive 2013 YTD

Mosquitoes

05.24 AMOR - EVS Week 20
05.24 AMOR - GRAVID Week 20
05.24 AMOR - NJLT Week 20

Horses

12.16 2010 Equine WNV Result Map
12.16 2010 Confirmed Equine Cases Report
05.26 2009 Equine WNV Result Map
- view report archives -