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

Case Counts by County

CountyDead birds
Alameda11
Alpine-
Amador-
Butte21
Calaveras-
Colusa-
Contra Costa26
Del Norte-
El Dorado4
Fresno6
Glenn4
Humboldt-
Imperial-
Inyo-
Kern-
Kings4
Lake4
Lassen-
Los Angeles113
Madera5
Marin5
Mariposa-
Mendocino-
Merced5
Modoc-
Mono-
Monterey-
Napa1
Nevada2
Orange76
Placer27
Plumas-
Riverside14
Sacramento408
San Benito-
San Bernardino5
San Diego252
San Francisco-
San Joaquin35
San Luis Obispo-
San Mateo11
Santa Barbara-
Santa Clara85
Santa Cruz2
Shasta3
Sierra-
Siskiyou-
Solano11
Sonoma8
Stanislaus10
Sutter10
Tehama-
Trinity-
Tulare3
Tuolumne-
Ventura30
Yolo71
Yuba4
Total1276

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

Human data is updated every Friday by 4pm. Dead bird data is updated every Wednesday and Friday by 4pm. Mosquito and sentinel chicken data are updated on Fridays by 4pm.

Due to different reporting schedules, case totals on this website may not always be consistent with those reported by local health departments.

April 17 - 23 is West Nile and Mosquito and Vector Control Awareness Week in California! This week highlights the importance of preventing mosquito bites and protecting Californians from mosquito-borne diseases. Stop by the "Fight the Bite" event at the State Capitol in Sacramento on Thursday, April 21st from 1:00 - 4:00pm for more information. Contact your local mosquito and vector control district to learn about events in your area.

Interactive Map

View the interactive map courtesy of http://maps.calsurv.org
- View Printable Map -

Total Counties with
WNV in 2016: 37

New counties highlighted in red.
Alameda, Butte, Colusa, Contra Costa, El Dorado, Fresno, Glenn, Kern, Kings, Lake, Los Angeles, Madera, Marin, Merced, Monterey, Napa, Nevada, Orange, Placer, Riverside, Sacramento, San Bernardino, San Diego, San Joaquin, San Mateo, Santa Clara, Santa Cruz, Shasta, Solano, Sonoma, Stanislaus, Sutter, Tehama, Tulare, Ventura, Yolo, and Yuba.

CDPH Confirms First Human West Nile Virus Death of 2016
SACRAMENTO - California Department of Public Health (CDPH) Director and State Health Officer Dr. Karen Smith today announced the first confirmed death in California due to West Nile virus (WNV). The deceased person was a senior citizen in Sacramento County.
Reporting a Dead Bird Video
- view news and press release archives -

human cases

YTD: 234 Counties: 27
There were 35 new WNV human cases reported in California last week from the following counties: Butte (2), Kings (1), Los Angeles (13), Madera (1), Monterey (1), Placer (3), San Diego (6), Stanislaus (1), Sutter (2), Tehama (1), Tulare (3), and Yolo (1). These are the first WNV human cases from Placer and Tulare counties this year. This is the first indication of WNV from Monterey County this year.

5 WNV-related fatalities have been reported to CDPH in Los Angeles (2), Sacramento (1), San Diego (1), and Yolo (1).

234 human cases from 27 counties have tested positive for WNV in 2016.

 

dead birds

YTD: 1,276 Counties: 33
There were 41 new WNV positive dead birds reported in California last week from the following counties: Contra Costa (3), Los Angeles (7), Orange (4), Riverside (2), Sacramento (3), San Diego (5), San Mateo (1), Santa Clara (7), Solano (4), Sonoma (1), Ventura (2), and Yolo (2).

1,276 dead birds from 33 counties have tested positive for WNV in 2016.

 

mosquito samples

YTD: 3,249 Counties: 30
There were 69 new WNV positive mosquito samples reported in California last week from the following counties: Butte (2), Contra Costa (1), Fresno (3), Lake (1), Los Angeles (29), Madera (5), Riverside (1), Sacramento (7), San Bernardino (1), San Joaquin (2), Santa Clara (1), Shasta (1), Sonoma (1), Stanislaus (6), Tulare (2), and Yolo (6).

3,249 mosquito samples from 30 counties have tested positive for WNV in 2016.

A mosquito sample may contain up to 50 individual mosquitoes.

 

sentinel chickens

YTD: 295 Counties: 17
There were 16 new WNV positive sentinel chickens reported in California last week from the following counties: Butte (1), Los Angeles (13), and Solano (2).

295 sentinel chickens from 17 counties have tested positive for WNV in 2016.

Be a West Nile Watcher

Help us track down the West Nile Virus by reporting all dead birds. You can submit an online report by clicking on the button on the right.

2003-2015 WNV Activity Summary

Element 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 Total
Human cases (fatal) 31 (0) 779 (29) 880 (19) 278 (7) 380 (21) 445 (15) 112 (4) 111 (6) 158 (9) 479 (20) 379 (15) 801 (31) 783 (53) 5,588 (229)
Horses 12 540 456 58 28 32 18 19 15 22 13 03 03 1,202
Dead birds 96 3,232 3,046 1,446 1,396 2,569 515 416 688 1,644 1,251 2,442 1,349 20,090
Mosquito samples 32 1,136 1,242 832 1,007 2,003 1,063 1,305 2,087 2849 2,528 3,340 3,329 22,753
Sentinel chickens 70 809 1,053 640 510 585 443 281 391 540 485 443 449 6,699
Squirrels - 49 48 32 26 32 10 24 24 23 03 03 03 276
1 There were 20 imported human cases. 2 There were 3 imported horse cases. 3 No longer monitored.

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 Sep 23, 2016201620155Y AVG
Counties374038
Human cases234233192
Dead birds12769691176
Mosquito samples324927692451
Sentinel chickens295314325
YTD - Year to date corresponds to the same time last year or last five years.

- view all 2015 YTD activity -

WNV Reports

Weekly Report

09.23 Arbovirus Bulletin #29
09.23 2016 YTD WNV Activity Map
09.20 2016 US Arboviral Activity Update

Humans

09.14 2016 Human WNV Incidence Report
09.14 2003-2016 WNV Case Summary
03.21 2015 Human WNV Incidence Report

Dead Birds

09.23Positive Species for 2016
09.23Reported, Tested, Positive 2016
09.23Positive Counts by City/County for 2016

Mosquitoes

09.23 AMOR - EVS Week 37
09.23 AMOR - GRAVID Week 37
09.23 AMOR - NJLT Week 37
- view report archives -