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
Printable Version
2014 | 2013 | 2012
2011 | 2010 | 2009
2008 | 2007

Human data is updated every Tuesday 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.
- View Printable Map -

Total Counties with
WNV in 2014: 40

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, Santa Cruz, Shasta, Solano, Sonoma, Stanislaus, Sutter, Tehama, Tulare, Ventura, Yolo, and Yuba.

West Nile Virus at Highest Level Ever in Mosquitoes
SACRAMENTO - Dr. Ron Chapman, director of the California Department of Public Health (CDPH) and state health officer, is reminding Californians to remain vigilant against the threat of West Nile virus.
- view news and press release archives -

NOTE:

human cases

YTD: 797 Counties: 31
There were 3 new WNV human cases reported in California this week from the following counties: Los Angeles (1), Orange (1), and Yuba (1).

29 WNV-related fatalities have been reported to CDPH from twelve local health jurisdictions: Glenn (1), Kern (1), Long Beach City (3), Los Angeles (6), Orange (7), Placer (1), Sacramento (2), San Diego (1), Shasta (1), Stanislaus (2), Sutter (3), and Tehama (1).

797 human cases from 31 counties have tested positive for WNV in 2014.

 

dead birds

YTD: 2,437 Counties: 36

2,437 dead birds from 36 counties have tested positive for WNV in 2014.

 

mosquito samples

YTD: 3,340 Counties: 30

3,340 mosquito samples from 30 counties have tested positive for WNV in 2014.

 

sentinel chickens

YTD: 443 Counties: 23

443 sentinel chickens from 23 counties have tested positive for WNV in 2014.

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2003-2013 WNV Activity Summary

Element 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 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) 4,004 (145)
Horses 12 540 456 58 28 32 18 19 15 22 13 1,202
Dead birds 96 3,232 3,046 1,446 1,396 2,569 515 416 688 1,644 1,251 16,299
Mosquito samples 32 1,136 1,242 832 1,007 2,003 1,063 1,305 2,087 2849 2,528 16,084
Sentinel chickens 70 809 1,053 640 510 585 443 281 391 540 485 5,807
Squirrels - 49 48 32 26 32 10 24 24 23 8 276
1 There were 20 imported human cases. 2 There were 3 imported horse cases.

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

As of Dec 22, 2014201420135Y AVG
Counties404440
Human cases797375245
Dead birds24371251902
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

12.22 2014 YTD WNV Activity Map
12.16 2014 US Arboviral Activity Update
12.12 Arbovirus Bulletin #42

Humans

12.22 2014 Human WNV Incidence Report
12.22 2003-2014 WNV Case Summary
08.12 2013 Human WNV Incidence Report

Dead Birds

12.22Reported, Tested, Positive 2014
12.22Positive Counts by City/County for 2014
12.22Positive 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 -