2011 West Nile Virus Activity
This map details mosquitoes, dead birds, chickens, and horses that have tested positive for West Nile virus. You can zoom in and out of the map and click on the placemarkers to get a detailed description of the date the positive activity was confirmed and the approximate location.
For information regarding human cases, please click here.
Mosquito Samples: 7
| n | Date Collected | City | Cross Streets | Species |
|---|---|---|---|---|
| 1 | 8/17 | Oakley | West Cypress Road x Ohara Ave. | Cx. tarsalis |
| 2 | 8/29 | Knightsen | Holland Tract x Old River | Cx. tarsalis |
| 3 | 8/31 | Brentwood | Sellers Ave. x Chestnut St. | Cx. pipiens |
| 4 | 9/8 | Brentwood | Sellers Ave. x Chestnut St. | Cx. pipiens |
| 5 | 9/21 | Concord | Minert Rd. x San Simeon Dr. | Cx. tarsalis |
| 6 | 10/3 | Concord | Bates Ave. x Mason Cir. | Cx. pipiens |
| 7 | 10/12 | Brentwood | Sellers Ave. x Chestnut St. | Cx. pipiens |
Dead Birds: 43
| n | Date Reported | City | Cross Streets | Species |
|---|---|---|---|---|
| 1 | 6/29 | Walnut Creek | Treat Blvd. x Bancroft Rd. | American Crow |
| 2 | 7/5 | Pittsburg | Loveridge Rd. x Buchanan Rd. | Western Scrub Jay |
| 3 | 7/25 | Antioch | Deer Valley Rd. x Sand Creek Rd. | American Crow |
| 4 | 8/19 | Concord | Oak Grove Rd. x Treat Blvd. | American Crow |
| 5 | 8/10 | Pleasant Hill | Monument Blvd. x Buskirk Ave. | American Crow |
| 6 | 8/10 | Alamo | Danville Blvd. x Camille Ave. | Western Scrub Jay |
| 7 | 8/23 | Concord | Treat Blvd. x Oak Grove Rd. | American Crow |
| 8 | 8/29 | Walnut Creek | Walnut Blvd. x Mountain View Blvd. | Western Scrub Jay |
| 9 | 8/31 | Knightsen | Delta Rd. x Knightsen Ave. | American Crow |
| 10 | 9/2 | Concord | Oak Grove Rd. x Monument Blvd. | Western Scrub Jay |
| 11 | 9/2 | Brentwood | Lone Tree Way x Fairview Ave. | American Crow |
| 12 | 9/6 | Walnut Creek | Bancroft Rd. x Oak Grove Rd. | American Crow |
| 13 | 8/25 | Oakley | W. Cypress Rd. x Empire Ave. | Western Scrub Jay |
| 14 | 9/7 | Concord | Oak Grove Rd. x Treat Blvd. | American Crow |
| 15 | 9/8 | Concord | Oak Grove Rd. x Minert Rd. | American Crow |
| 16 | 9/5 | Brentwood | Hwy 4 Bypass x Balfour Rd. | Western Scrub Jay |
| 17 | 9/1 | Concord | Oak Grove Rd. x Minert Rd. | Western Scrub Jay |
| 18 | 9/12 | Pleasant Hill | Ellinwood Dr. x Contra Costa Blvd. | American Crow |
| 19 | 9/12 | Lafayette | Old tunnel Rd. x Pleasant Hill Rd. | American Crow |
| 20 | 9/12 | Concord | David Ave. x Mohr Ln. | Western Scrub Jay |
| 21 | 9/14 | Brentwood | Main St. x Sycamore Ave. | American Crow |
| 22 | 9/14 | Pleasant Hill | Gergory Ln. x Contra Costa Blvd. | American Crow |
| 23 | 9/18 | Concord | Minert Rd. x Oak Grove Rd. | American Crow |
| 24 | 9/19 | Walnut Creek | Walnut Ave. x Oak Grove Rd. | Western Scrub Jay |
| 25 | 9/20 | Concord | Hwy 4 x Hwy 242 | American Crow |
| 26 | 9/22 | Concord | Farm Bureau Rd. x Concord Blvd. | American Crow |
| 27 | 9/22 | Pleasant Hill | Contra Costa Blvd. x Taylor Blvd. | American Crow |
| 28 | 9/23 | Concord | Cowell Rd. x Coventry Rd. | Western Scrub Jay |
| 29 | 9/19 | Concord | Cowell Rd. x Treat Blvd. | Western Scrub Jay |
| 30 | 9/14 | Discovery Bay | Starboard Dr. x Willow Lake Rd. | Western Scrub Jay |
| 31 | 9/30 | Walnut Creek | Oak Grove Rd. x Mitchell Dr. | Western Scrub Jay |
| 32 | 10/1 | Concord | Willow Pass Rd. x Grant St. | American Crow |
| 33 | 10/4 | Pleasant Hill | Boyd Rd. x Contra Costa Blvd. | American Crow |
| 34 | 10/4 | Concord | Olivera Rd. x Port Chicago Hwy | American Crow |
| 35 | 10/5 | Concord | Treat Blvd. x Clayton Rd. | American Crow |
| 36 | 10/6 | Oakley | Hwy 4 x Oakley Rd. | American Crow |
| 37 | 10/7 | Concord | San Jose Ave. x Clayton Rd. | American Crow |
| 38 | 10/11 | Concord | Clayton Rd. x Farm Bureau Rd. | American Crow |
| 39 | 10/11 | Pleasant Hill | Viking Dr. x Contra Costa Blvd. | American Crow |
| 40 | 10/12 | Oakley | W. Cypress Rd. x Empire Ave. | American Crow |
| 41 | 10/14 | Concord | San Simeon Dr. x Treat Blvd. | American Crow |
| 42 | 10/14 | Pleasant Hill | Boyd Rd. x Patterson Blvd. | American Crow |
| 43 | 10/14 | Concord | San Simeon Dr. x Treat Blvd. | American Crow |
Sentinel Chicken Flocks: 0
| #/10 | Date Bleed | Area |
|---|---|---|
Note: Chickens do not die from West Nile virus. They develop antibodies to the virus which is detected in their blood.
Horses: 0
| n | Date Reported | City | Dead/Euthanized |
|---|---|---|---|
| 1 | 9/17/15 | Brentwood | No |