Case Counts by County

CountyDead birds
Alameda96
Alpine-
Amador-
Butte22
Calaveras-
Colusa4
Contra Costa44
Del Norte-
El Dorado7
Fresno9
Glenn4
Humboldt2
Imperial-
Inyo-
Kern3
Kings3
Lake18
Lassen-
Los Angeles99
Madera5
Marin6
Mariposa-
Mendocino-
Merced8
Modoc-
Mono-
Monterey-
Napa12
Nevada-
Orange431
Placer40
Plumas-
Riverside1
Sacramento294
San Benito-
San Bernardino17
San Diego35
San Francisco-
San Joaquin53
San Luis Obispo-
San Mateo20
Santa Barbara2
Santa Clara925
Santa Cruz1
Shasta6
Sierra-
Siskiyou-
Solano33
Sonoma37
Stanislaus47
Sutter19
Tehama-
Trinity-
Tulare40
Tuolumne-
Ventura7
Yolo71
Yuba16
Total2437

WNV Activity by County
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2008 | 2007

Press Releases

CALIFORNIA DEPARTMENT OF PUBLIC HEALTH ANNOUNCES FIRST CONFIRMED HUMAN WEST NILE VIRUS CASE IN 2008

Jun 20, 2008

NUMBER: PH08-34
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), today announced that a Tulare County woman has tested positive for West Nile virus (WNV) infection, the first reported human case in California this year. She was not hospitalized and is recovering.

"The first human West Nile virus infection of 2008 underscores the importance of taking precautions to protect from mosquito bites," Horton said. "Californians should use insect repellent and eliminate all sources of standing water that can support mosquito breeding."

To date this year, WNV activity has been detected in 19 of California's 58 counties. In 2007, the first human case in California was reported on June 20th.

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. 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:


  • DEET - Apply inspect repellent containing DEET, picaradin, oil of lemon eucalyptus or IR 3535 according to label instructions. Repellents keep the mosquitoes from biting you. DEET can be used safely on infants and children 2 months of age and older.

  • DRESS - Wear clothing that reduces the risk of skin exposure.

  • DAWN AND DUSK - Mosquitoes that carry WNV bite in the early morning and evening so it is important to wear repellent at this time. Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens with tears or holes.

  • DRAIN - Mosquitoes lay their eggs on standing water. Eliminate all sources of standing water on your property, including flower pots, old car tires, rain gutters and pet bowls. If you have a pond, use mosquito fish or commercially available products to eliminate mosquito larvae.

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 previous year and previous five-year average to date

As of Dec 16, 2014201420135Y AVG
Counties404440
Human cases794375241
Dead birds24371251901
Mosquito samples334025281966
Sentinel chickens443485428
YTD - Year to date corresponds to the same time last year or last five years.

- view all 2013 YTD activity -

WNV Reports

Weekly Report

12.16 2014 US Arboviral Activity Update
12.16 2014 YTD WNV Activity Map
12.12 Arbovirus Bulletin #42

Humans

12.16 2014 Human WNV Incidence Report
12.16 2003-2014 WNV Case Summary
08.12 2013 Human WNV Incidence Report

Dead Birds

12.16Reported, Tested, Positive 2014
12.16Positive Counts by City/County for 2014
12.16Positive Species for 2014

Mosquitoes

11.07 AMOR - EVS Week 44
11.07 AMOR - GRAVID Week 44
11.07 AMOR - NJLT Week 44
- view report archives -