Case Counts by County

CountyDead birds
Alameda-
Alpine-
Amador-
Butte-
Calaveras-
Colusa-
Contra Costa38
Del Norte-
El Dorado2
Fresno15
Glenn2
Humboldt-
Imperial-
Inyo-
Kern4
Kings9
Lake1
Lassen-
Los Angeles227
Madera3
Marin-
Mariposa-
Mendocino-
Merced9
Modoc-
Mono-
Monterey-
Napa-
Nevada1
Orange49
Placer10
Plumas-
Riverside7
Sacramento134
San Benito-
San Bernardino33
San Diego-
San Francisco-
San Joaquin27
San Luis Obispo-
San Mateo-
Santa Barbara-
Santa Clara36
Santa Cruz-
Shasta-
Sierra-
Siskiyou-
Solano1
Sonoma-
Stanislaus24
Sutter2
Tehama1
Trinity-
Tulare42
Tuolumne-
Ventura1
Yolo9
Yuba1
Total688

WNV Activity by County
Printable Version
2010 | 2009 | 2008 | 2007

Human data is updated every Tuesday and Friday by 4pm. Dead bird and squirrel data are updated every Wednesday by 4pm. Horse, mosquito and sentinel chicken data are updated on Fridays by 4pm.
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Total Counties with
WNV in 2011: 36

Alameda, Amador, Butte, Contra Costa, El Dorado, Fresno, Glenn, Imperial, Inyo, Kern, Kings, Lake, Los Angeles, Madera, Merced, Nevada, Orange, Placer, Riverside, Sacramento, San Bernardino, San Diego, San Joaquin, Santa Barbara, Santa Clara, Santa Cruz, Shasta, Solano, Sonoma, Stanislaus, Sutter, Tehama, Tulare, Ventura, Yolo, and Yuba.

Mosquito Control Matters video (MVCAC)
This video illustrates the importance of mosquito control and how we live, work and play in our communities would be drastically altered without it.

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National Activity
As of December 13, 2011, 667 human cases of WNV had been reported nationwide in 42 states and the District of Columbia: Alabama (5), Arizona (58), Arkansas (1), California (154), Colorado (7), Connecticut (9), Delaware (1), District of Columbia (4), Florida (23), Georgia (12), Idaho (2), Illinois (34), Indiana (9), Iowa (9), Kansas (4), Kentucky (5), Louisiana (10), Maryland (20), Massachusetts (5), Michigan (33), Minnesota (2), Mississippi (52), Missouri (10), Montana (1), Nebraska (28), Nevada (16), New Jersey (7), New Mexico (4), New York (43), North Carolina (2), North Dakota (4), Ohio (21), Pennsylvania (6), Rhode Island (1), South Dakota (2), Tennessee (18), Texas (26), Utah (3), Vermont (1), Virginia (8), West Virginia (1), Wisconsin (3), and Wyoming (3). Of the 667 cases, 458 (69%) developed neuroinvasive disease. As of December 13, 2011, a total of 42 WNV-related fatalities had been reported in Alabama (1), Arizona (4), California (8), Florida (2), Georgia (3), Illinois (3), Indiana (1), Kansas (1), Kentucky (1), Michigan (2), Minnesota (1), Mississippi (5), Nevada (2), New York (2), Ohio (1), Tennessee (2), Texas (2), and Virginia (1).

human cases

YTD: 155 Counties: 23
There have been 8 fatalities from Kern (3), Los Angeles (4), and Tehama (1) counties in 2011. 155 human cases from 23 counties have tested positive for WNV in 2011.
 

horses

YTD: 15 Counties: 7
15 horses from 7 counties have tested positive for WNV in 2011.
 

dead birds

YTD: 688 Counties: 26
There were 2 new WNV positive dead birds reported in California this week from Orange County. [More info]
688 dead birds from 26 counties have tested positive for WNV in 2011.
 

mosquito samples

YTD: 2,087 Counties: 26
2,087 mosquito samples from 26 counties have tested positive for WNV in 2011.
 

sentinel chickens

YTD: 391 Counties: 15

391 sentinel chickens from 15 counties have tested positive for WNV in 2011.
 

squirrels

YTD: 24 Counties: 6
24 squirrels from 6 counties have tested positive for WNV in 2011.

Be a West Nile Watcher

Help us track down the West Nile Virus by reporting all dead birds and squirrels. Call 1-877-968-2473 to report a dead bird or squirrel or you can submit an online report.

2004-2010 WNV Activity Summary

Element 2003 2004 2005 2006 2007 2008 2009 2010 Total
Human cases (fatal) 31 (0) 779 (29) 880 (19) 278 (7) 380 (21) 445 (15) 112 (4) 111 (6) 2,988 (101)
Horses 12 540 456 58 28 32 18 19 1,152
Dead birds 96 3,232 3,046 1,446 1,396 2,569 515 416 12,716
Mosquito samples 32 1,136 1,242 832 1,007 2,003 1063 1,305 8,620
Sentinel chickens 70 809 1,053 640 510 585 443 281 4,391
Squirrels - 49 48 32 26 32 10 24 221
1 There were 20 imported human cases. 2 There were 3 imported horse cases.

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Compared to 2010 YTD

As of Jan 24, 201220102011
Counties3536
Human cases106155
Horses1915
Dead birds416688
Mosquito samples13052087
Sentinel chickens281391
Squirrels2424
2010 YTD - Year to date corresponds to the same time last year.

- view all 2010 YTD activity -

WNV Reports

Weekly Report

01.242011 WNV Activity by County
01.24 2011 YTD WNV Activity Map
01.10 US Arboviral Activity Update

Humans

12.16 2011 Human WNV Case Linelist
12.16 2011 Human WNV Incidence Report
12.16 2003-2011 WNV Case Summary

Dead Birds

01.24Positive Counts by City/County for 2011
01.24Reported, Tested, Positive 2011 YTD
01.24Positive Species for 2011

Mosquitoes

11.14 AMOR - EVS Week 44
11.14 AMOR - GRAVID Week 44
11.14 AMOR - NJLT Week 44

Horses

12.16 2010 Equine WNV Result Map
12.16 2010 Confirmed Equine Cases Report
05.26 2009 Equine WNV Result Map
- view report archives -