Case Counts by County

CountyHuman cases
Alameda1
Alpine-
Amador-
Butte6
Calaveras1
Colusa1
Contra Costa4
Del Norte-
El Dorado1
Fresno3
Glenn1
Humboldt-
Imperial-
Inyo-
Kern2
Kings2
Lake-
Lassen-
Los Angeles153
Madera-
Marin-
Mariposa-
Mendocino-
Merced1
Modoc-
Mono-
Monterey-
Napa-
Nevada-
Orange71
Placer6
Plumas-
Riverside62
Sacramento13
San Benito-
San Bernardino30
San Diego34
San Francisco-
San Joaquin12
San Luis Obispo-
San Mateo-
Santa Barbara-
Santa Clara1
Santa Cruz-
Shasta1
Sierra-
Siskiyou-
Solano1
Sonoma-
Stanislaus17
Sutter-
Tehama4
Trinity-
Tulare4
Tuolumne-
Ventura-
Yolo1
Yuba-
Total433

WNV Activity by County
Printable Version
2008 | 2007

Human data is updated every Tuesday by 4pm. Dead bird and squirrel data are updated every Wednesday by 4pm. Horse, mosquito and sentinel chicken data are updated every Friday by 4pm.
- View Printable Map -

Total Counties with
WNV in 2008: 49

Alameda, Amador, Butte, Calaveras, Colusa, Contra Costa, Del Norte, El Dorado, Fresno, Glenn, Humboldt, Imperial, Kern, Kings, Lake, Lassen, Los Angeles, Madera, Marin, Mendocino, Merced, Modoc, Mono, Monterey, Napa, Nevada, Orange, Placer, Riverside, Sacramento, San Bernardino, San Diego, San Joaquin, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Shasta, Solano, Sonoma, Stanislaus, Sutter, Tehama, Trinity, Tulare, Ventura, Yolo, and Yuba.

WNV News
WNV-Carrying Mosquitoes Still a Threat in the Fall 09/26/08
Summer has ended but mosquitoes are still active. Californians need to continue to use repellent and protect themselves from mosquitoes that carry West Nile virus. The risk of getting West Nile virus is higher in southern California this year than the last few years. Mosquito and vector control agencies throughout the state continue to monitor and control West Nile virus.
CALIFORNIA DEPARTMENT OF PUBLIC HEALTH ANNOUNCES FIRST DEATH FROM WEST NILE VIRUS IN 2008 08/25/08
SACRAMENTO - Dr. Mark Horton, director of the California Department of Public Health (CDPH), announced today that West Nile virus (WNV) has claimed the life of an elderly woman in Orange County. She is the first death this year in California from complications associated with the virus.
- view news and press release archives -

National Activity
As of December 16, 2008, 1,370 human cases had been reported nationwide this year in the following 42 states: Alabama (21), Arizona (109), Arkansas (9), California (411), Colorado (95), Connecticut (8), Delaware (1), Florida (2), Georgia (8), Idaho (33), Illinois (19), Indiana (3), Iowa (10), Kansas (38), Kentucky (3), Louisiana (36), Maryland (14), Michigan (17), Minnesota (21), Mississippi (99), Missouri (19), Montana (5), Nebraska (49), Nevada (16), New Jersey (7), New Mexico (9), New York (44), North Dakota (43), Ohio (20), Oklahoma (7), Oregon (16), Pennsylvania (14), Rhode Island (1), South Dakota (39), Tennessee (17), Texas (62), Utah (26), Virginia (1), Washington (2), West Virginia (1), Wisconsin (7), and Wyoming (8). Of the 1,370 individuals, 640 (47%) had neuroinvasive illness. As of December 16, 37 fatalities had been reported in Arizona (5), California (13), Colorado (1), Idaho (1), Iowa (1), Illinois (1), Mississippi (3), Missouri (1), New Jersey (1), New York (6), Ohio (1), Pennsylvania (1), Texas (1), and Wisconsin (1). At this time last year, 3,404 human cases had been reported nationwide.

human cases

YTD: 433 Counties: 26

Fifteen WNV-related fatalities have been reported in Fresno (1), Los Angeles (6), Orange (4), Riverside (4) and San Bernardino (1) counties. A total of 69 WNV-positive blood donation samples have been reported this year; 21 of the individuals reported symptoms and were reclassified as cases.

433 human cases from 26 counties have tested positive for WNV in 2008.

 

horses

YTD: 32 Counties: 14
32 horses from 14 counties have tested positive for WNV in 2008.
 

dead birds

YTD: 2,530 Counties: 46
2,530 dead birds from 46 counties have tested positive for WNV in 2008.
 

mosquito samples

YTD: 2,001 Counties: 26
2,001 mosquito samples from 26 counties have tested positive for WNV in 2008.
 

sentinel chickens

YTD: 584 Counties: 27

There have been a total of 129 positive flocks in 2008 from the following counties: Butte (6), Calaveras (1), Colusa (1), Contra Costa (2), Fresno (5), Glenn (1), Imperial (6), Kern (4), Kings (1), Lake (1), Los Angeles (34), Madera (1), Merced (2), Orange (1), Placer (4), Riverside (18), Sacramento (3), San Bernardino (12), San Diego (3), San Joaquin (2), Shasta (1), Solano (3), Stanislaus (7), Sutter (3), Tulare (4), Ventura (2), and Yuba (1).

584 sentinel chickens from 27 counties have tested positive for WNV in 2008.
 

squirrels

YTD: 32 Counties: 7
32 squirrels from 7 counties have tested positive for WNV in 2008.

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.

2003-2007 WNV Activity Summary

Element 2003 2004 2005 2006 2007 Total
Human cases (fatal) 31 (0) 779 (29) 880 (19) 278 (7) 380 (21) 2,320 (76)
Click here for a printable version of the 2004-2008 WNV Case Summary
Element 2003 2004 2005 2006 2007 Total
Horses 12 540 456 58 28 1,083
Dead birds 96 3,232 3,046 1,446 1,395 9,215
Mosquito samples 32 1,136 1,242 832 1,007 4,249
Sentinel chickens 70 809 1,053 640 510 3,082
Squirrels - 49 48 32 26 155
1 There were 20 imported human cases. 2 There were 3 imported horse cases.

Locate Your Local Mosquito and Vector Control Agency
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Compared to 2007 YTD

As of 01/02/09 20072008
Counties5149
Human cases380433
Horses2832
Dead birds13952530
Mosquito samples10072001
Sentinel chickens510584
Squirrels2632
2007 YTD - Year to date corresponds to the same time last year.

- view all 2007 YTD activity -

WNV Reports

Weekly Report

01.09 Arbovirus Bulletin #1
01.092008 WNV Activity by County
12.19 Arbovirus Bulletin #43

Humans

01.09 2008 Human WNV Case Linelist
01.09 2008 Summary Table of Human Infection
01.09 2004-2008 WNV Case Summary

Dead Birds

01.09Reported, Tested, Positive 2007 YTD
01.09Positive Counts by City/County for 2008
01.09Reported, Tested, Positive 2008

Mosquitoes

12.19 Submission Data for 12/15/08 - 12/19/08
12.12 Submission Data for 12/8/08 - 12/12/08
12.05 Submission Data for 11/24/08 - 12/5/08

Sentinel Chickens

12.12 Submission Data for 12/8/08 - 12/12/08
11.21 Submission Data for 11/17/08 - 11/21/08
11.14 Submission Data for 11/10/08 - 11/14/08

Horses

11.10 Confirmed Equine Cases
10.04 2007 Equine WNV Result Map
- view report archives -