Case Counts by County

CountyHuman cases
Alameda1
Alpine-
Amador-
Butte5
Calaveras1
Colusa1
Contra Costa4
Del Norte-
El Dorado1
Fresno3
Glenn-
Humboldt-
Imperial-
Inyo-
Kern1
Kings1
Lake-
Lassen-
Los Angeles144
Madera-
Marin-
Mariposa-
Mendocino-
Merced1
Modoc-
Mono-
Monterey-
Napa-
Nevada-
Orange65
Placer6
Plumas-
Riverside60
Sacramento13
San Benito-
San Bernardino24
San Diego22
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-
Total394

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

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

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 November 4, 2008, 1,200 human cases had been reported nationwide this year in the following 42 states: Alabama (20), Arizona (97), Arkansas (8), California (329), Colorado (77), Connecticut (8), Delaware (1), Florida (2), Georgia (7), Idaho (32), Illinois (19), Indiana (3), Iowa (9), Kansas (31), Kentucky (3), Louisiana (36), Maryland (13), Michigan (17), Minnesota (21), Mississippi (98), Missouri (16), Montana (5), Nebraska (37), Nevada (15), New Jersey (7), New Mexico (8), New York (41), North Dakota (43), Ohio (19), Oklahoma (7), Oregon (4), Pennsylvania (13), Rhode Island (1), South Dakota (39), Tennessee (12), Texas (58), Utah (25), Virginia (1), Washington (2), West Virginia (1), Wisconsin (7), and Wyoming (8). Of the 1,200 individuals, 550 (46%) had neuroinvasive illness. As of November 7, 27 fatalities had been reported in Arizona (4), California (7), Iowa (1), Illinois (1), Mississippi (3), Missouri (1), New Jersey (1), New York (6), Ohio (1), Texas (1), and Wisconsin (1). At this time last year, 3,265 human cases had been reported nationwide.

human cases

YTD: 394 Counties: 25
There have been 2 new WNV positive human cases reported in California this week from Riverside (2) counties. Of the 394 individuals, 254 (64%) developed neuroinvasive symptoms. The median age of the 394 individuals is 55 years (range: 3-94 years), and 247 (63%) are male. Thirteen WNV-related fatalities have been reported in Fresno (1), Los Angeles (5), Orange (2), 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. 394 human cases from 25 counties have tested positive for WNV in 2008.
 

horses

YTD: 32 Counties: 14
There was 1 new WNV positive horse reported in California last week from San Bernardino County. 32 horses from 14 counties have tested positive for WNV in 2008.
 

dead birds

YTD: 2,509 Counties: 46
There were 8 new WNV positive dead birds reported in California this week from the following counties: San Diego (6), and Santa Clara (2). 2,509 dead birds from 46 counties have tested positive for WNV in 2008.
 

mosquito samples

YTD: 1,956 Counties: 26
There were 3 new WNV positive mosquito samples reported in California last week from the following counties: Los Angeles (1), and San Bernardino (2). 1,956 mosquito samples from 26 counties have tested positive for WNV in 2008.
 

sentinel chickens

YTD: 580 Counties: 27
There were 4 new WNV positive sentinel chickens reported in California this week from the following counties: Kern (1), Lake (2), and Riverside (1). This is the first WNV positive sentinel chicken from Lake County this year.

There have been a total of 127 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), Los Angeles (33), 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).

580 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 11/19/08 20072008
Counties5149
Human cases375394
Horses2832
Dead birds13812509
Mosquito samples10041956
Sentinel chickens510576
Squirrels2632
2007 YTD - Year to date corresponds to the same time last year.

- view all 2007 YTD activity -

WNV Reports

Weekly Report

11.202008 WNV Activity by County
11.17 Comparative Line Graphs of West Nile Virus Activity
11.14 Arbovirus Bulletin #39

Humans

11.18 2008 Human WNV Case Linelist
11.18 2008 Summary Table of Human Infection
11.18 2004-2008 WNV Case Summary

Dead Birds

11.20Reported, Tested, Positive 2007 YTD
11.20Positive Counts by City/County for 2008
11.20Reported, Tested, Positive 2008

Mosquitoes

11.14 Submission Data for 11/10/08 - 11/14/08
11.07 Submission Data for 11/3/08 - 11/7/08
11.07 AMOR - NJLT 5 Year Average Week 44

Sentinel Chickens

11.14 Submission Data for 11/10/08 - 11/14/08
11.07 Submission Data for 11/3/08 - 11/7/08
10.31 Submission Data for 10/27/08 - 10/31/08

Horses

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