Skip to main content

2020 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: 13
nDate CollectedCityCross StreetsSpecies
18/10/20ByronByron Hwy x Rankin RdCulex tarsalis
28/17/20KnightsenPalm TractCulex pipiens
38/24/20Discovery BayCherry Hills Dr x Hwy 4Culex pipiens
48/25/20BrentwoodFrench Dr x Fletcher LnCulex tarsalis
58/25/20BrentwoodBrentwoodCulex pipiens
68/25/20BrentwoodOutrigger Cir x Breakwater WyCulex pipiens
78/25/20BrentwoodBougainvilla Dr Walnut BlvdCulex tarsalis
88/31/20BrentwoodElkins Wy x Iparq WyCulex pipiens
99/8/20Discovery BayCherry Hills Dr x Wayfarer DrCulex tarsalis
109/8/20BrentwoodRutherford Cir x Devonshire LpCulex tarsalis
119/8/20BrentwoodRutherford Cir x Devonshire LpCulex pipiens
129/21/20BrentwoodElkins Wy x Iparq WyCulex pipiens
139/21/20MartinezInterstate 680 x Waterfront RdCulex tarsalis
Dead Birds: 22
nDate ReportedCityCross StreetsSpecies
18/15/20MartinezAlhambra Ave x Alhambra Valley RdCA Scrub Jay
28/22/20BrentwoodRutherford Cir x Devonshire LpCA Scrub Jay
38/22/20BrentwoodPeachwillow Dr x Central BlvdAmerican Crow
48/23/20BrentwoodMcClaren Rd x French DrAmerican Crow
58/24/20AntiochDallas Ranch Rd x Prewett Ranch DrAmerican Crow
68/25/20BrentwoodArmstrong Rd x Walnut BlvdAmerican Crow
78/25/20BrentwoodCrescent Dr x Claremont DrCA Scrub Jay
88/29/20BrentwoodIronwood Dr x San Jose DrCA Scrub Jay
98/30/20Discovery BaySand Point Rd x Discovery Bay BlvdAmerican Crow
108/31/20BrentwoodSand Creek Rd x Highland WyCA Scrub Jay
118/31/20BrentwoodPescara Blvd x Castello Ranch RdAmerican Crow
128/31/20BrentwoodAutumn Valley Wy x Sutter Creek WyCA Scrub Jay
139/2/20BrentwoodWoodside Dr x Minnesota AveAmerican Crow
149/3/20ConcordRicardo Dr x Salvio StAmerican Crow
159/8/20BrentwoodBrookwood Ct x Glenwillow DrCA Scrub Jay
169/19/20Walnut CreekWimbledon Rd x Ygnacio Valley RdAmerican Crow
179/21/20BrentwoodSofia Ct x Antica DrCA Scrub Jay
1810/3/20BrentwoodBalfour Rd x Bixler RdCA Scrub Jay
199/28/20BrentwoodArmstron Rd x Carey LnAmerican Crow
2010/6/20ConcordMinert Rd x Waltrip LnCA Scrub Jay
2110/8/20BrentwoodCipriani Pl x La Pergola DrAmerican Crow
2210/14/20BrentwoodGiotto Dr x Sofia WyAmerican Crow


Sentinel Chicken Flocks: 3
#/10Date BleedArea
 2/109/8/20Holland Tract

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