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
Orange78
Placer28
Plumas-
Riverside14
Sacramento408
San Benito-
San Bernardino5
San Diego254
San Francisco-
San Joaquin35
San Luis Obispo-
San Mateo11
Santa Barbara-
Santa Clara85
Santa Cruz2
Shasta3
Sierra-
Siskiyou-
Solano11
Sonoma8
Stanislaus12
Sutter10
Tehama-
Trinity-
Tulare3
Tuolumne-
Ventura30
Yolo71
Yuba4
Total1283

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

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: 276 Counties: 28
There were 42 new WNV human cases reported in California this week from the following counties: Fresno (1), Glenn (1), Kern (1), Lake (1), Los Angeles (16), Madera (2), Orange (6), Placer (2), Riverside (1), San Bernardino (3), San Diego (2), San Joaquin (1), Stanislaus (1), and Tulare (4). This is the first WNV human case from Lake County this year.

9 WNV-related fatalities have been reported to CDPH in Los Angeles (3), Sacramento (1), San Diego (1), San Joaquin (1), Stanislaus (1), Yolo (1), and Tulare (1).

276 human cases from 28 counties have tested positive for WNV in 2016.

 

dead birds

YTD: 1,283 Counties: 33
There were 7 new WNV positive dead birds reported in California this week from the following counties: Orange (2), Placer (1), San Diego (2), and Stanislaus (2).

1,283 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: 296 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).

296 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.

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Compared to previous year and previous five-year average to date

As of Sep 30, 2016201620155Y AVG
Counties374038
Human cases276300233
Dead birds128310161237
Mosquito samples324928902551
Sentinel chickens296330354
YTD - Year to date corresponds to the same time last year or last five years.

- view all 2015 YTD activity -

WNV Reports

Weekly Report

09.30 2016 YTD WNV Activity Map
09.27 2016 US Arboviral Activity Update
09.23 Arbovirus Bulletin #29

Humans

09.30 2016 Human WNV Incidence Report
09.30 2003-2016 WNV Case Summary
03.21 2015 Human WNV Incidence Report

Dead Birds

09.30Positive Species for 2016
09.30Reported, Tested, Positive 2016
09.30Positive Counts by City/County for 2016

Mosquitoes

09.30 AMOR - EVS Week 38
09.30 AMOR - GRAVID Week 38
09.30 AMOR - NJLT Week 38
- view report archives -