2014 Contra Costa West Nile Virus Activity

For information regarding human cases, please click here.

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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.



Mosquito Samples: 6

n Date Reported City Cross Streets Species
1 6/23/14 Knightsen Holland Tract Area Culex tarsalis
2 7/7/14 Discovery Bay Cherry Hills Dr. Culex pipiens
3 7/7/14 Martinez I-680 x Waterfront Rd. Culex tarsalis
4 7/14/14 Discovery Bay Cherry Hills Dr. x Marina Rd. Culex pipiens
5 7/16/14 Discovery Bay Bixler Rd. x Balfour Rd. Culex pipiens
6 7/17/14 Discovery Bay Cherry Hills Drive x Wayfarer Drive Culex tarsalis

Dead Birds: 19

n Date Reported City Cross Streets Species
1 4/23/14 Alamo Danville Blvd. x Camille Ave. American Crow
2 5/18/14 Pleasant Hill Monument Blvd. x Mohr Ln. American Crow
3 6/9/14 San Ramon Norris Canyon Rd. x Bollinger Canyon Rd. American Crow
4 614/14 Oakley Empire Ave. x Main St. American Crow
5 6/17/14 Oakley Empire Ave. x Hemlock Dr. American Crow
6 6/17/14 Oakley Empire Ave. x Hemlock Dr. American Crow
7 6/20/14 Brentwood Lone Tree Wy x O'Hara Ave. American Crow
8 6/25/14 Antioch Hillcrest Ave. x Sunset. Dr. American Crow
9 6/26/14 San Ramon Bollinger Canyon Rd. x Norris Canyon Rd. American Crow
10 7/2/14 Bethel Island Bethel Island Rd. x Gateway Rd. American Crow
11 7/9/14 Walnut Creek Arroyo Wy. x N. Broadway American Crow
12 7/10/14 Oakley Kay Ave. x O'Hara Ave. Western Scrub Jay
13 7/13/14 Antioch Camby Rd. x G St. Western Scrub Jay
14 7/14/14 Brentwood Foothill Dr. x Balfour Rd. American Crow
15 7/16/14 Danville Hartford Rd. x Danville Blvd. American Crow
16 7/17/14 Antioch Hargrove St. x E. 18th St. American Crow
17 7/17/14 Brentwood Minnesota Ave. x Windmeadows Dr. Western Scrub Jay
18 7/21/14 Antioch Judsonville Dr. x Hansen Dr. Western Scrub Jay
19 7/23/14 Concord Bancroft Rd. x Hookston Rd. Western Scrub Jay

Sentinel Chicken Flocks: 2

# of Chickens out of 10 (10 per Flock) Date Bled Area
1/10 6/16/14 Holland Tract
3/10 6/30/14 Holland Tract
1/10 7/14/14 Holland Tract
1/10 7/14/14 Oakley

Horses: 0

n Date Reported City Dead/Euthanized


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