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2017 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.

May contain: cutlery, spoon, chart, and plot

 For information regarding human cases, please click here.


Mosquito Samples: 9
nDate CollectedCityCross StreetsSpecies
17/26/17DIscovery BayPoint of TImber Rd. x Poe Dr.Culex pipiens
28/2/17ByronByron Hwy x Rankin Rd.Culex tarsalis
38/16/17AntiochE. 18th St. x Hillcrest Ave.Culex tarsalis
48/21/17Discovery BayCherry Hills Dr. x Hwy 4Culex pipiens
58/23/17BrentwoodContinente Ave x Date Nut St.Culex pipiens
69/11/17OakleyOakley Rd. x Main St.Culex tarsalis
79/27/17KnightsenHolland Tract Rd. x Tranquility Bay Rd.Culex tarsalis
810/2/17KnightsenHolland Tract Rd. x Tranquility Bay Rd.Culex tarsalis
910/23/17MartinezI-680 x Waterfront Rd.Culex tarsalis
Dead Birds: 19
nDate ReportedCityCross StreetsSpecies
17/26/2017Walnut CreekYgnacio Valley Rd. x Wiget Ln.American Crow
27/26/2017Walnut CreekYgnacio Valley Rd. x Wiget Ln.American Crow
38/1/2017Walnut CreekYgnacio Valley Rd. x Wiget Ln.American Crow
48/3/2017DanvilleBrookside Dr. x Greenbrook Dr.American Crow
58/8/2017Discovery BayHighway 4 x Discovery Bay Blvd.Western Scrub Jay
68/24/2017DanvilleCamino Tassajara x Fairwood Ct.Western Scrub Jay
79/7/2017San RamonDavona Dr. x Calais DriveAmerican Crow
89/8/2017BrentwoodByron Hwy. x Delta Rd.American Crow
99/10/2017AntiochHillcrest Ave. x Via Dora Dr.American Crow
109/12/2017Pleasant HillGregory Ln. x Contra Costa Blvd.American Crow
119/18/2017AlamoGolden Meadow Ln. x Red Wing Dr.Western Scrub Jay
129/21/2017Walnut CreekArbolado Dr. x Doncaster Dr.American Crow
139/24/2017Walnut CreekNorris Rd. x San Miguel Dr.American Crow
149/27/2017Pleasant HillViking Dr. x Norse Dr.American Crow
159/27/2017MartinezLester Rd. x Milden Rd.Western Scrub Jay
169/27/2017Walnut CreekN. California Blvd. x Pringle Ave.Western Scrub Jay
1710/1/2017Walnut CreekPalmer Rd. x Rudgear Rd.American Crow
1810/2/2017MartinezAlhambra Valley Rd. x Chelsea Dr.American Crow
1910/1/2017Walnut CreekBurlington Wy x Woodstock Ct.American Crow


Sentinel Chicken Flocks: 2
#/10Date BleedArea

Note: Chickens do not die from West Nile virus. They develop antibodies to the virus which is detected in their blood.


Horses: 0
nDate ReportedCityDead/Euthanized