Case Counts by County

CountyDead birds
Alameda92
Alpine-
Amador-
Butte22
Calaveras-
Colusa4
Contra Costa44
Del Norte-
El Dorado5
Fresno9
Glenn4
Humboldt2
Imperial-
Inyo-
Kern3
Kings3
Lake18
Lassen-
Los Angeles97
Madera5
Marin6
Mariposa-
Mendocino-
Merced8
Modoc-
Mono-
Monterey-
Napa12
Nevada-
Orange386
Placer40
Plumas-
Riverside1
Sacramento293
San Benito-
San Bernardino17
San Diego23
San Francisco-
San Joaquin53
San Luis Obispo-
San Mateo18
Santa Barbara1
Santa Clara897
Santa Cruz1
Shasta6
Sierra-
Siskiyou-
Solano33
Sonoma37
Stanislaus47
Sutter19
Tehama-
Trinity-
Tulare40
Tuolumne-
Ventura7
Yolo71
Yuba16
Total2340

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.
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Total Counties with
WNV in 2014: 40

New counties highlighted in red.
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: 562 Counties: 29
There were 74 new WNV human cases reported in California last week from the following counties: Butte (1), Contra Costa (1), Fresno (3), Los Angeles (31), Orange (29), Riverside (1), San Diego (2), San Joaquin (1), Santa Clara (1), Tehama (1), and Tulare (3).

17 WNV-related fatalities have been reported to CDPH from nine local health jurisdictions: Glenn (1), Long Beach City (1), Los Angeles (2), Orange (5), Sacramento (2), Shasta (1), Stanislaus (2), Sutter (2), and Tehama (1).

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

 

dead birds

YTD: 2,340 Counties: 36
There were 26 new WNV positive dead birds reported in California last week from the following counties: Contra Costa (1), Los Angeles (2), Placer (1), Sacramento (2), San Diego (4), San Joaquin (1), Santa Barbara (1), Santa Clara (9), and Sonoma (5). This is the first indication of WNV from Santa Barbara County this year.

2,340 dead birds from 36 counties have tested positive for WNV in 2014.

 

mosquito samples

YTD: 3,268 Counties: 30
There were 58 new WNV positive mosquito samples reported in California last week from the following counties: Contra Costa (2), Fresno (2), Los Angeles (20), Orange (15), San Bernardino (2), San Diego (1), San Joaquin (13), and Stanislaus (3). This is the first WNV positive mosquito sample from San Diego County this year.

3,268 mosquito samples from 30 counties have tested positive for WNV in 2014.

 

sentinel chickens

YTD: 412 Counties: 23
There were 17 new WNV positive sentinel chickens reported in California last week from the following counties: Los Angeles (11), Nevada (2), Shasta (3), and Sutter (1). This is the first indication of WNV from Nevada County this year.

412 sentinel chickens from 23 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 Oct 17, 2014201420135Y AVG
Counties404139
Human cases562272173
Dead birds23401198866
Mosquito samples326824891924
Sentinel chickens412463394
YTD - Year to date corresponds to the same time last year or last five years.

- view all 2013 YTD activity -

WNV Reports

Weekly Report

10.17 Arbovirus Bulletin #35
10.17 2014 YTD WNV Activity Map
10.10 Arbovirus Bulletin #34

Humans

10.13 2014 Human WNV Incidence Report
10.13 2003-2014 WNV Case Summary
08.12 2013 Human WNV Incidence Report

Dead Birds

10.17Reported, Tested, Positive 2014
10.17Positive Counts by City/County for 2014
10.17Positive Species for 2014

Mosquitoes

10.17 AMOR - EVS Week 41
10.17 AMOR - GRAVID Week 41
10.17 AMOR - NJLT Week 41
- view report archives -