Case Counts by County

CountyDead birds
Alameda13
Alpine-
Amador-
Butte1
Calaveras-
Colusa1
Contra Costa18
Del Norte-
El Dorado1
Fresno6
Glenn1
Humboldt-
Imperial-
Inyo-
Kern2
Kings-
Lake5
Lassen-
Los Angeles7
Madera3
Marin2
Mariposa-
Mendocino-
Merced-
Modoc-
Mono-
Monterey-
Napa1
Nevada-
Orange43
Placer10
Plumas-
Riverside-
Sacramento112
San Benito-
San Bernardino2
San Diego1
San Francisco-
San Joaquin19
San Luis Obispo-
San Mateo3
Santa Barbara-
Santa Clara429
Santa Cruz1
Shasta2
Sierra-
Siskiyou-
Solano26
Sonoma6
Stanislaus14
Sutter11
Tehama-
Trinity-
Tulare31
Tuolumne-
Ventura1
Yolo16
Yuba3
Total791

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

Press Releases

CALIFORNIA DEPARTMENT OF PUBLIC HEALTH ANNOUNCES FIRST DEATH FROM WEST NILE VIRUS IN 2008

Aug 25, 2008

NUMBER: PH08-46
FOR RELEASE: IMMEDIATE
CONTACT: Suanne Buggy or Lea Brooks
http://www.cdph.ca.gov        
(916) 440-7259

SACRAMENTO - Dr. Mark Horton, director of the California Department of Public Health (CDPH), announced today that West Nile virus (WNV) has claimed the life of an elderly woman in Orange County. She is the first death this year in California from complications associated with the virus.

"This unfortunate death reminds us that we must take precautions to protect ourselves and our families from mosquito bites," Horton said. "Californians should use insect repellent and eliminate all sources of standing water that can support mosquito breeding."

To date in 2008, WNV activity has been detected in 38 of California's 58 counties. In addition to the death, 96 people have become ill with WNV infections in 13 counties. WNV also has been detected in 1,295 dead birds, 1,101 mosquito samples, five horses, 109 sentinel chickens and nine squirrels.

Last year at this time, WNV activity had been detected in 48 counties and 148 people had been confirmed with WNV infections, including nine deaths.

WNV is transmitted to humans and animals through a mosquito bite. Mosquitoes become infected when they feed on infected birds.

Most individuals who are infected with WNV will not experience any illness. However, individuals 50 years of age and older have a higher chance of getting sick and are more likely to develop serious symptoms when infected with WNV. Recent data also indicate that those with diabetes and/or hypertension are at greatest risk for serious illness.

The most effective ways for individuals to prevent exposure to mosquito bites and WNV are:

  • Apply insect repellent containing DEET, picaradin or oil of lemon eucalyptus, according to label instructions.
  • Ensure doors and windows have tight-fitting screens. Repair or replace screens that have tears or holes.
  • Eliminate all sources of standing water that can support mosquito breeding.
  • Wear clothing that reduces the risk of skin exposure and avoid spending time outside at dusk and dawn when mosquitoes are most active.
Most individuals who are infected with WNV will not experience any illness. Individuals 50 years of age and older have a higher chance of getting sick and are more likely to develop serious symptoms when infected with WNV. Recent data also indicate that those with diabetes and/or hypertension are at greatest risk for serious illness.

California's WNV Web site - http://www.westnile.ca.gov - includes the latest information on WNV activity in the state. In order to help identify WNV activity, Californians are encouraged to report all dead birds and dead tree squirrels on the Web site or by calling toll-free 1-877-WNV-BIRD (968-2473).

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Compared to 2013 YTD

As of Jul 23, 201420132014
Counties3234
Human cases415
Dead birds325791
Mosquito samples555771
Sentinel chickens2714
2013 YTD - Year to date corresponds to the same time last year.

- view all 2013 YTD activity -

WNV Reports

Weekly Report

07.23 2014 YTD WNV Activity Map
07.18 Arbovirus Bulletin #22
07.15 2014 US Arboviral Activity Update

Humans

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

Dead Birds

07.23Reported, Tested, Positive 2014
07.23Positive Counts by City/County for 2014
07.23Positive Species for 2014

Mosquitoes

07.18 AMOR - EVS Week 28
07.18 AMOR - GRAVID Week 28
07.18 AMOR - NjLT Week 28

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 -