Case Counts by County

CountyDead birds
Alameda92
Alpine-
Amador-
Butte22
Calaveras-
Colusa4
Contra Costa44
Del Norte-
El Dorado5
Fresno9
Glenn4
Humboldt2
Imperial-
Inyo-
Kern3
Kings3
Lake18
Lassen-
Los Angeles97
Madera5
Marin6
Mariposa-
Mendocino-
Merced8
Modoc-
Mono-
Monterey-
Napa12
Nevada-
Orange386
Placer40
Plumas-
Riverside1
Sacramento293
San Benito-
San Bernardino17
San Diego23
San Francisco-
San Joaquin53
San Luis Obispo-
San Mateo18
Santa Barbara1
Santa Clara897
Santa Cruz1
Shasta6
Sierra-
Siskiyou-
Solano33
Sonoma37
Stanislaus47
Sutter19
Tehama-
Trinity-
Tulare40
Tuolumne-
Ventura7
Yolo71
Yuba16
Total2340

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 previous year and previous five-year average to date

As of Oct 17, 2014201420135Y AVG
Counties404139
Human cases562272173
Dead birds23401198866
Mosquito samples326824891924
Sentinel chickens412463394
YTD - Year to date corresponds to the same time last year or last five years.

- view all 2013 YTD activity -

WNV Reports

Weekly Report

10.17 Arbovirus Bulletin #35
10.17 2014 YTD WNV Activity Map
10.10 Arbovirus Bulletin #34

Humans

10.13 2014 Human WNV Incidence Report
10.13 2003-2014 WNV Case Summary
08.12 2013 Human WNV Incidence Report

Dead Birds

10.17Reported, Tested, Positive 2014
10.17Positive Counts by City/County for 2014
10.17Positive Species for 2014

Mosquitoes

10.17 AMOR - EVS Week 41
10.17 AMOR - GRAVID Week 41
10.17 AMOR - NJLT Week 41
- view report archives -