Case Counts by County

CountyDead birds
Alameda84
Alpine-
Amador-
Butte19
Calaveras-
Colusa4
Contra Costa36
Del Norte-
El Dorado3
Fresno9
Glenn4
Humboldt2
Imperial-
Inyo-
Kern3
Kings2
Lake15
Lassen-
Los Angeles57
Madera5
Marin3
Mariposa-
Mendocino-
Merced1
Modoc-
Mono-
Monterey-
Napa12
Nevada-
Orange278
Placer38
Plumas-
Riverside1
Sacramento271
San Benito-
San Bernardino12
San Diego7
San Francisco-
San Joaquin45
San Luis Obispo-
San Mateo13
Santa Barbara-
Santa Clara821
Santa Cruz1
Shasta5
Sierra-
Siskiyou-
Solano32
Sonoma17
Stanislaus39
Sutter19
Tehama-
Trinity-
Tulare38
Tuolumne-
Ventura4
Yolo63
Yuba16
Total1979

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: 37

Alameda, Butte, Colusa, Contra Costa, El Dorado, Fresno, Glenn, Humboldt, Imperial, Kern, Kings, Lake, Los Angeles, Madera, Marin, 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: 238 Counties: 26
There were 57 new WNV human cases reported in California last week from the following counties: Butte (4), Fresno (1), Glenn (2), Imperial (1), Kern (2), Kings (2), Lake (1), Los Angeles (6), Orange (24), Riverside (1), San Bernardino (2), San Diego (2), San Joaquin (1), Santa Clara (2), Stanislaus (3), Sutter (1), Tulare (1), and Yuba (1). These are the first WNV human cases from Kings, Lake, Riverside, and San Diego counties this year.

9 WNV-related fatalities have been reported in to CDPH from in six counties: Glenn (1), Orange (2), Sacramento (1), Shasta (1), Stanislaus (2), and Sutter (2).

238 human cases from 26 counties have tested positive for WNV in 2014.

 

dead birds

YTD: 1,979 Counties: 35
There were 152 new WNV positive dead birds reported in California last week from the following counties: Alameda (11), Contra Costa (2), El Dorado (2), Fresno (1), Los Angeles (10), Madera (1), Napa (3), Orange (50), Placer (11), Riverside (1), Sacramento (15), San Bernardino (1), San Joaquin (3), San Mateo (4), Santa Clara (20), Sonoma (2), Stanislaus (4), Ventura (2), and Yolo (9). This is the first WNV positive dead bird from Riverside County this year.

1,979 dead birds from 35 counties have tested positive for WNV in 2014.

 

mosquito samples

YTD: 2,853 Counties: 29
There were 193 new WNV positive mosquito samples reported in California last week from the following counties: Butte (1), Contra Costa (1), Fresno (4), Kern (9), Kings (7), Lake (1), Los Angeles (24), Madera (4), Orange (42), Placer (2), Riverside (10), Sacramento (25), San Bernardino (3), San Joaquin (12), San Mateo (1), Shasta (1), Sonoma (1), Stanislaus (28), Tulare (2), and Yolo (15).

2,853 mosquito samples from 29 counties have tested positive for WNV in 2014.

 

sentinel chickens

YTD: 302 Counties: 20
There were 28 new WNV positive sentinel chickens reported in California last week from the following counties: Lake (2), Los Angeles (11), Riverside (4), San Bernardino (7), Santa Clara (1), Shasta (1), and Yolo (2).

302 sentinel chickens from 20 counties have tested positive for WNV in 2014.

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.

2003-2013 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 Sep 12, 2014201420135Y AVG
Counties374136
Human cases23811774
Dead birds19791022678
Mosquito samples285321731643
Sentinel chickens302330253
YTD - Year to date corresponds to the same time last year or last five years.

- view all 2013 YTD activity -

WNV Reports

Weekly Report

09.12 Arbovirus Bulletin #30
09.12 2014 YTD WNV Activity Map
09.09 2014 US Arboviral Activity Update

Humans

09.09 2014 Human WNV Incidence Report
09.09 2003-2014 WNV Case Summary
08.12 2013 Human WNV Incidence Report

Dead Birds

09.12Reported, Tested, Positive 2014
09.12Positive Counts by City/County for 2014
09.12Positive Species for 2014

Mosquitoes

09.12 AMOR - EVS Week 36
09.12 AMOR - GRAVID Week 36
09.12 AMOR - NJLT Week 36
- view report archives -