Case Counts by County

CountyDead birds
Alameda13
Alpine-
Amador-
Butte2
Calaveras-
Colusa1
Contra Costa19
Del Norte-
El Dorado1
Fresno7
Glenn1
Humboldt1
Imperial-
Inyo-
Kern2
Kings1
Lake5
Lassen-
Los Angeles9
Madera4
Marin2
Mariposa-
Mendocino-
Merced-
Modoc-
Mono-
Monterey-
Napa5
Nevada-
Orange55
Placer16
Plumas-
Riverside-
Sacramento143
San Benito-
San Bernardino2
San Diego1
San Francisco-
San Joaquin23
San Luis Obispo-
San Mateo3
Santa Barbara-
Santa Clara429
Santa Cruz1
Shasta2
Sierra-
Siskiyou-
Solano27
Sonoma8
Stanislaus17
Sutter13
Tehama-
Trinity-
Tulare32
Tuolumne-
Ventura1
Yolo21
Yuba5
Total872

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

Special - Resources

West Nile Virus Information for Physicians

Aug 3, 2012

West Nile virus (WNV) has been detected in many regions of the state. Physicians should:


  • Be aware if WNV is active in their area
  • Look for symptoms of WNV
  • Test for WNV because testing:

    • differentiates WNV from other conditions (enterovirus, other arboviral diseases) and thus may prompt a change in treatment regime
    • results offer anticipatory guidance--both WNV neuroinvasive disease and WN fever patients can have lingering symptoms and knowing the underlying etiology is helpful for the patient and family members
    • helps mosquito control and public health agencies institute proper control measures to reduce the risk of further cases in the event of a positive result

  • Contact their local public health department for details on sample submission and testing


For additional information, please see these resources:

Locate Your Local Mosquito and Vector Control Agency
Search by Zip Code

Compared to 2013 YTD

As of Jul 25, 201420132014
Counties3335
Human cases415
Dead birds325872
Mosquito samples761980
Sentinel chickens7939
2013 YTD - Year to date corresponds to the same time last year.

- view all 2013 YTD activity -

WNV Reports

Weekly Report

07.25 Arbovirus Bulletin #23
07.25 2014 YTD WNV Activity Map
07.18 Arbovirus Bulletin #22

Humans

07.21 2014 Human WNV Incidence Report
07.21 2003-2014 WNV Case Summary
04.21 2013 Human WNV Incidence Report

Dead Birds

07.25Reported, Tested, Positive 2014
07.25Positive Counts by City/County for 2014
07.25Positive Species for 2014

Mosquitoes

07.25 AMOR - EVS Week 29
07.25 AMOR - GRAVID Week 29
07.25 AMOR - NJLT Week 29

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 -