Case Counts by County

CountyDead birds
Alameda19
Alpine-
Amador-
Butte38
Calaveras-
Colusa3
Contra Costa11
Del Norte-
El Dorado4
Fresno3
Glenn4
Humboldt2
Imperial-
Inyo-
Kern1
Kings3
Lake5
Lassen-
Los Angeles103
Madera1
Marin3
Mariposa-
Mendocino-
Merced3
Modoc-
Mono-
Monterey-
Napa7
Nevada10
Orange83
Placer21
Plumas-
Riverside82
Sacramento103
San Benito-
San Bernardino25
San Diego355
San Francisco-
San Joaquin18
San Luis Obispo-
San Mateo23
Santa Barbara3
Santa Clara231
Santa Cruz-
Shasta16
Sierra-
Siskiyou-
Solano10
Sonoma11
Stanislaus14
Sutter16
Tehama-
Trinity2
Tulare23
Tuolumne-
Ventura26
Yolo61
Yuba6
Total1349

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

Data on this website is updated every Friday by 4pm.

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

Interactive Map

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

Total Counties with
WNV in 2015: 41

Alameda, Butte, Colusa, Contra Costa, El Dorado, Fresno, Glenn, Humboldt, Imperial, Kern, Kings, Lake, Los Angeles, Madera, Marin, Mendocino, Merced, Napa, Nevada, Orange, Placer, Riverside, Sacramento, San Bernardino, San Diego, San Joaquin, San Mateo, Santa Barbara, Santa Clara, Shasta, Siskiyou, Solano, Sonoma, Stanislaus, Sutter, Tehama, Trinity, Tulare, Ventura, Yolo, and Yuba.

WNV Dead Bird Hotline Update
The West Nile Virus Dead Bird Hotline is staffed with live hotline operators. Please call the hotline at 877-WNV-BIRD (877-968-2473) to report a dead bird, OR click the button below to submit an online report.
- view news and press release archives -

human cases

YTD: 737 Counties: 31
There were 30 new WNV human cases reported in California this week from the following counties: Los Angeles (19), Mendocino (1), Orange (6), Riverside (1), San Bernardino (1), San Diego (1), and Yuba (1).

45 WNV-related fatalities have been reported in to CDPH from Butte (1), Kern (1), Los Angeles (18), Nevada (1), Orange (7), Pasadena City (1), Riverside (6), San Bernardino (3), San Diego (5), and Ventura (2)

737 human cases from 31 counties have tested positive for WNV in 2015.

 

dead birds

YTD: 1,349 Counties: 37
There was 1 new WNV positive dead bird reported in California this week from San Diego County.

1,349 dead birds from 37 counties have tested positive for WNV in 2015.

 

mosquito samples

YTD: 3,329 Counties: 29

3,329 mosquito samples from 29 counties have tested positive for WNV in 2015.

 

sentinel chickens

YTD: 449 Counties: 22

449 sentinel chickens from 22 counties have tested positive for WNV in 2015.

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.

2003-2014 WNV Activity Summary

Element 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 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) 4,805 (176)
Horses 12 540 456 58 28 32 18 19 15 22 13 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 18,741
Mosquito samples 32 1,136 1,242 832 1,007 2,003 1,063 1,305 2,087 2849 2,528 3,340 19,424
Sentinel chickens 70 809 1,053 640 510 585 443 281 391 540 485 443 6,250
Squirrels - 49 48 32 26 32 10 24 24 23 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?

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

As of Dec 30, 2015201520145Y AVG
Counties414032
Human cases737801362
Dead birds134924421205
Mosquito samples332933402161
Sentinel chickens449443372
YTD - Year to date corresponds to the same time last year or last five years.

- view all 2014 YTD activity -

WNV Reports

Weekly Report

01.12 2015 US Arboviral Activity Update
01.12 2015 YTD WNV Activity Map
12.18 Arbovirus Bulletin #41

Humans

01.06 2015 Human WNV Incidence Report
01.06 2003-2015 WNV Case Summary
03.09 2014 Human WNV Incidence Report

Dead Birds

01.12Positive Species for 2015
01.12Positive Counts by City/County for 2015
01.12Reported, Tested, Positive 2015

Mosquitoes

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