Case Counts by County

CountyDead birds
Alameda90
Alpine-
Amador-
Butte22
Calaveras-
Colusa4
Contra Costa42
Del Norte-
El Dorado5
Fresno9
Glenn4
Humboldt2
Imperial-
Inyo-
Kern3
Kings3
Lake18
Lassen-
Los Angeles81
Madera5
Marin5
Mariposa-
Mendocino-
Merced7
Modoc-
Mono-
Monterey-
Napa12
Nevada-
Orange331
Placer39
Plumas-
Riverside1
Sacramento287
San Benito-
San Bernardino15
San Diego7
San Francisco-
San Joaquin50
San Luis Obispo-
San Mateo16
Santa Barbara-
Santa Clara878
Santa Cruz1
Shasta6
Sierra-
Siskiyou-
Solano33
Sonoma26
Stanislaus45
Sutter19
Tehama-
Trinity-
Tulare40
Tuolumne-
Ventura5
Yolo68
Yuba16
Total2195

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: 38

Alameda, Butte, Colusa, Contra Costa, El Dorado, Fresno, Glenn, Humboldt, Imperial, Kern, Kings, Lake, Los Angeles, Madera, Marin, Mendocino, Merced, Napa, 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.

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: 428 Counties: 29
There were 53 new WNV human cases reported in California this week from the following counties: Butte (1), Colusa (1), Contra Costa (1), Fresno (3), Los Angeles (18), Merced (1), Orange (18), San Bernardino (3), Santa Clara (1), Stanislaus (2), Tulare (3), and Yolo (1). This is the first WNV human case from Merced County this year.

15 WNV-related fatalities have been reported in to CDPH from in eight local health jurisdictions: Glenn (1), Long Beach City (1), Los Angeles (2), Orange (4), Sacramento (2), Shasta (1), Stanislaus (2), and Sutter (2).

428 human cases from 29 counties have tested positive for WNV in 2014.

 

dead birds

YTD: 2,195 Counties: 35
There were 39 new WNV positive dead birds reported in California this week from the following counties: Alameda (1), Butte (2), Contra Costa (1), Los Angeles (11), Orange (5), Sacramento (2), San Bernardino (2), and Santa Clara (15).

2,195 dead birds from 35 counties have tested positive for WNV in 2014.

 

mosquito samples

YTD: 3,047 Counties: 29
There were 96 new WNV positive mosquito samples reported in California last week from the following counties: Contra Costa (1), Fresno (5), Kern (7), Kings (3), Los Angeles (20), Merced (1), Orange (29), Riverside (4), Sacramento (2), San Bernardino (5), San Joaquin (10), Stanislaus (7), and Yolo (2).

3,047 mosquito samples from 29 counties have tested positive for WNV in 2014.

 

sentinel chickens

YTD: 361 Counties: 21
There were 33 new WNV positive sentinel chickens reported in California last week from the following counties: Lake (1), Los Angeles (14), Merced (1), Riverside (16), and Santa Clara (1).

361 sentinel chickens from 21 counties have tested positive for WNV in 2014.

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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.

2003-2013 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 Oct 01, 2014201420135Y AVG
Counties384138
Human cases428205136
Dead birds21951144811
Mosquito samples304723791818
Sentinel chickens361404329
YTD - Year to date corresponds to the same time last year or last five years.

- view all 2013 YTD activity -

WNV Reports

Weekly Report

10.01 2014 YTD WNV Activity Map
09.30 2014 US Arboviral Activity Update
09.19 Arbovirus Bulletin #31

Humans

09.29 2014 Human WNV Incidence Report
09.29 2003-2014 WNV Case Summary
08.12 2013 Human WNV Incidence Report

Dead Birds

10.01Reported, Tested, Positive 2014
10.01Positive Counts by City/County for 2014
10.01Positive Species for 2014

Mosquitoes

09.26 Arbovirus Bulletin #32
09.26 AMOR - EVS Week 38
09.26 AMOR - GRAVID Week 38
- view report archives -