CA Dept. of Public Health UC Davis Arbovirus Research and Training Mosquito and Vector Control Assoc. of CA

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 Angeles-
Madera-
Marin-
Mariposa-
Mendocino-
Merced-
Modoc-
Mono-
Monterey-
Napa-
Nevada-
Orange1
Placer-
Plumas-
Riverside-
Sacramento-
San Benito-
San Bernardino-
San Diego1
San Francisco-
San Joaquin-
San Luis Obispo-
San Mateo1
Santa Barbara-
Santa Clara-
Santa Cruz-
Shasta-
Sierra-
Siskiyou-
Solano-
Sonoma-
Stanislaus-
Sutter-
Tehama-
Trinity-
Tulare-
Tuolumne-
Ventura-
Yolo-
Yuba-
Total3

WNV Activity by County
Printable Version
2017 | 2016 | 2015 | 2014
2013 | 2012 | 2011
2010 | 2009 | 2008
2007

Press Releases

CDPH Reports First Human West Nile Virus Infections This Season

Jun 20, 2014

SACRAMENTO - The first two human infections with West Nile virus this season have been reported by Contra Costa and San Joaquin Counties, announced Dr. Ron Chapman, director of the California Department of Public Health (CDPH) and state health officer. The patient from Contra Costa County has since recovered and been released from the hospital, and the patient from San Joaquin County has tested positive for the virus but is not showing symptoms at this time.

"These reported West Nile virus cases remind us that taking a few minutes to protect ourselves and our families from mosquito bites can make a big difference," said Chapman. "West Nile virus activity is greatest during the summer."

West Nile virus is transmitted to humans and animals by the bite of an infected mosquito. The risk of serious illness to most people is low. However, some individuals - less than 1 percent - can develop a serious neurologic illness such as encephalitis or meningitis. People 50 years of age and older have a higher chance of getting sick and are more likely to develop complications. Recent data also indicate that those with diabetes and/or hypertension are at greatest risk for serious illness.

To date in 2014, West Nile virus has been detected in mosquitoes and birds in 19 California counties.

CDPH recommends that individuals prevent exposure to mosquito bites and West Nile virus by practicing the "Three Ds":


1. DEET - Apply insect repellent containing DEET, picaradin, oil of lemon eucalyptus or IR3535 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.

2. DAWN AND DUSK - Mosquitoes bite in the early morning and evening so it is important to wear proper clothing and repellent if outside during these times. Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens with tears or holes.

3. DRAIN - Mosquitoes lay their eggs on standing water. Eliminate or drain all sources of standing water on your property, including buckets, old car tires, rain gutters, birdbaths, and pet bowls. If you know of a swimming pool that is not being properly maintained, please contact your local mosquito and vector control agency.

California's West Nile virus website includes the latest information on West Nile virus activity in the state. Californians are encouraged to report all dead birds on the website or by calling toll-free 1-877-WNV-BIRD (968-2473).

Downloads


Having problems with mosquitoes?

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 Mar 30, 2017201720165Y AVG
Counties335
Human cases000
Dead birds3116
Mosquito samples000
Sentinel chickens000
YTD - Year to date corresponds to the same time last year or last five years.

- view all 2016 YTD activity -

WNV Reports

Weekly Report

04.21 Arbovirus Bulletin #3
04.14 Arbovirus Bulletin #2
04.07 Arbovirus Bulletin #1

Humans

02.08 2016 Human WNV Incidence Report
02.08 2003-2016 WNV Case Summary
03.21 2015 Human WNV Incidence Report

Dead Birds

04.21Positive Counts by City/County for 2017
04.21Positive Species for 2017
04.21Reported, Tested, Positive 2017

Mosquitoes

04.21 AMOR - EVS Week 15
04.21 AMOR - GRAVID Week 15
04.21 AMOR - NJLT Week 15
- view report archives -