Record Rainfall Creates Perfect Conditions for Mosquitoes (4/18/23)

First Dead Bird from San Pablo and More Mosquitoes Test Positive for West Nile Virus in Contra Costa County (9/24/21)

More Mosquitoes Test Positive for West Nile Virus in Contra Costa County (9/10/21)

First Dead Bird of 2021 Tests Positive for West Nile Virus in Contra Costa County (9/3/21)

More Mosquitoes Test Positive for West Nile Virus in Discovery Bay(8/13/21) 

More Mosquitoes Test Positive for West Nile Virus in Contra Costa County (7/16/21) 

First Sign of West Nile Virus of 2021 - Contra Costa County Mosquitoes Test Positive (7/2/21)

WNV Risk in Contra Costa County Continues As More Birds and Sentinel Chickens Test Positive (9/18/20)

Continued Risk of West Nile Virus as More Mosquitoes Test Positive (9/11/20)

West Nile Virus Risk Increases As More Mosquitoes and Birds Test Positive for West Nile Virus in Contra Costa County (9/4/20)

More Mosquitoes, Birds Test Positive for West Nile Virus in Contra Costa County (8/28/20)

West Nile Virus Confirmed in Dead Bird and Mosquitoes in Contra Costa County (8/21/20)

First Sign of West Nile Virus Activity Confirmed in Mosquitoes in Contra Costa County (8/14/20)

First Sign of West Nile Virus Activity of 2019 in Contra Costa County (9/6/19)

West Nile Virus Persists - More Mosquitoes, A Bird, Chickens Test Positive (9/21/18)

More Mosquitoes and Birds Test Positive As West Nile Virus Activity Continues (8/31/18)

West Nile Activity Continues As More Mosquitoes Test Positive for the Virus (8/24/18)

West Nile Activity Increases As Birds, Mosquitoes, and Chickens Test Positive for the Virus (8/17/18)

Risk Grows as Birds, Mosquitoes Test Positive for West Nile Virus (8/10/18)

West Nile Virus Confirmed in Mosquitoes and First Dead Bird of the Year (8/3/18)

West Nile Virus Confirmed in Central Contra Costa County 7/26/18)

West Nile Virus Confirmed in Mosquitoes in Contra Costa County (7/19/18)

First Sign of West Nile Virus Activity of 2018 in Contra Costa County (7/13/18)

WEST NILE VIRUS ACTIVITY CONTINUES IN CONTRA COSTA COUNTY. More dead birds, chickens, and mosquitoes test positive for the virus.(10/10/17)

MOSQUITOES, DEAD BIRDS, AND CHICKEN TEST POSITIVE FOR WEST NILE VIRUS. Two Contra Costa County Residents Also Test Positive for the Virus. (10/3/17)

WEST NILE VIRUS CONFIRMED IN MOSQUITOES AND BIRDS IN CONTRA COSTA COUNTY (9/15/17)

MOSQUITOES TEST POSITIVE FOR WEST NILE VIRUS IN BRENTWOOD (8/28/17)

MORE WEST NILE VIRUS DETECTED IN ANTIOCH AND DISCOVERY BAY (8/23/17)

DEAD BIRDS, HORSE, CHICKENS TEST POSITIVE FOR WEST NILE VIRUS IN DANVILLE, DISCOVERY BAY, BRENTWOOD, AND KNIGHTSEN AREA (8/17/17)

DEAD BIRD, MOSQUITOES WEST NILE VIRUS POSITIVE IN WALNUT CREEK & BYRON (8/10/17)

DEAD BIRDS, MOSQUITOES MARK FIRST WEST NILE VIRUS ACTIVITY THIS YEAR (7/31/17)

MOSQUITOES POSITIVE FOR WEST NILE VIRUS IN BETHEL ISLAND (10/28/16)

FOUR MORE DEAD BIRDS POSITIVE FOR WEST NILE VIRUS IN CONTRA COSTA COUNTY (10/14/16)

MORE BIRDS, MOSQUITOES POSITIVE FOR WEST NILE VIRUS IN CONTRA COSTA COUNTY (10/6/16)

THREE DEAD BIRDS AND ONE GROUP OF MOSQUITOES TEST POSITIVE FOR WEST NILE VIRUS IN CONTRA COSTA COUNTY(9/22/16)

THREE DEAD BIRDS AND TWO GROUPS OF MOSQUITOES TEST POSITIVE FOR WEST NILE VIRUS IN CONTRA COSTA COUNTY (9/9/16)

TWO GROUPS OF MOSQUITOES IN EAST COUNTY AND ONE DEAD BIRD IN CONCORD POSITIVE FOR WEST NILE VIRUS (9/1/16)

WEST NILE VIRUS CONTINUES WITH MORE DEAD BIRDS AND CHICKENS (8/25/16)

FIVE MORE DEAD BIRDS & A CHICKEN WITH WEST NILE VIRUS IN CONTRA COSTA COUNTY (8/10/16)

WEST NILE VIRUS ACTIVITY RAMPS UP IN CENTRAL AND EAST CONTRA COSTA COUNTY (8/4/16)

BIRD, CHICKENS POSITIVE FOR WEST NILE VIRUS IN OAKLEY (7/29/16)

MOSQUITOES WITH WEST NILE VIRUS FOUND NEAR KNIGHTSEN AND ANTIOCH (7/22/16)

WEST NILE VIRUS RISK INCREASES AS THREE MORE DEAD BIRDS TEST POSITIVE (7/14/16)

DEAD BIRD POSITIVE FOR WEST NILE VIRUS FIRST FOR 2016 (6/14/16)

Mosquitoes and Chicken in Martinez Test Positive for West Nile Virus (10/19/15)

Mosquitoes in Pittsburg and Bird in Danville Test Positive For West Nile Virus (10/14/15)

Chickens in Oakley and Bird in Danville Test Positive for West Nile Virus (9/20/15)

Mosquitoes in Discovery Bay and Antioch Positive for West Nile Virus (9/24/15)

More Chickens Test Positive for WNV in Contra Costa County (9/16/15)

Martinez Waterfront Latest Location for West Nile Virus Mosquitoes (8/19/15)

Pleasant Hill Dead Bird Positive for West Nile Virus (8/13/15)

West Nile Virus Detected in More Chickens in Eastern Contra Costa County (8/6/15)

First Chickens of 2015 Test Positive for West Nile Virus in East Contra Costa County (7/23/15)

West Nile Virus Detected in First Mosquitoes of 2015 in Contra Costa County (6/17/15)

West Nile Virus Activity Steadfast with Reports of Virus-Positive People, Mosquitoes, Birds (10/10/14)

Mosquito Populations Up As Season Draws Down (10/3/14)

Different Mosquito Species Targeted in East Contra Costa County (9/19/14)

Lack of Habit Wreaks Havoc for West Nile Virus Risk - Are You Raising Mosquitoes? (9/12/14)

Risk of West Nile Virus Continues Despite Unofficial End of Summer (9/5/14)

Protect Yourself from West Nile Virus This Labor Day Weekend at Home and Afar (8/29/14)

Fogging Efforts Successful in Concord; Elevated Risk of West Nile Virus in East County Continues (8/22/14)

Infected Mosquitoes Still a Threat in East County (8/14/14)

Higher Risk of West Nile Virus Continues in East Bay - New Activity in Pinole (8/8/14)

Risk of West Nile Virus Continues in Contra Costa County as More Mosquitoes, Birds and Chickens Test Positive (7/25/14)

West Nile Virus Infected Mosquitoes Prompt Spraying in Discovery Bay and Martinez (7/15/14)

West Nile Virus Activity Heats Up in Contra Costa County (7/9/14)

West Nile Virus Detected in Mosquitoes, Chicken and Birds in East County (7/1/14)

First Detection This Year of West Nile Virus in Oakley (6/20/14)

First Dead Bird Tested This Year is West Nile Virus Positive in Contra Costa County (4/25/14)

San Ramon Dead Bird Tests Positive for West Nile Virus (6/11/14)

Two People from East County and One Bird from Alamo Positive For West Nile Virus as Mosquito Season Winds Down (10/18/13)

Antioch Newest City for West Nile Virus Mosquitoes (9/20/13)

Dead Birds Reminder of Disease Threat (9/12/13)

Widespread West Nile Virus Activity Continues (9/6/13)

East Contra Costa County Focus of West Nile Virus Activity (8/30/13)

West Nile Virus Activity Moves Full Speed Ahead With Positive Birds, Chickens, and Mosquitoes (8/22/13)

Steady Stream of WNV continues; first death in San Joaquin County (8/15/13)

August a Critical Month for WNV (8/8/13)

West Nile Virus Claims Eight More Birds (7/31/13)

West Nile Activity Ramps Up With Six More Infected Birds (7/25/13)

More West Nile Virus Activity in Discovery Bay and Now Alamo (7/18/13)

Brentwood, Concord and Discovery Bay Current Areas of Concern for West Nile Virus (7/11/13)

First Mosquitoes Test Positive for West Nile Virus in 2013 Season (7/2/13)

First Dead Bird Tests Positive For 2013 West Nile Virus Season in Contra Costa County (6/27/13)

Mother Nature Prolongs Mosquito Season-More Dead Birds (10/17/12)

Cooler Weather Welcome as More Dead Birds Test Positive for Virus (10/11/12)

More Birds Positive; Heat Prolongs West Nile Virus Season (10/4/12)

West Nile Virus Season Not Slowing Down (9/20/12)

Elevated Risk of West Nile Virus Remains in East County (9/12/12)

Elevated Risk of West Nile Virus Continues in East Contra Costa County (9/6/12)

Eight More Birds Positive For West Nile Virus in Contra Costa County (8/30/12)

More Mosquitoes Test Positive for WNV in Brentwood - Fogging Planned (8/22/12)

Hot Weather Increases West Nile Virus Risk - Fogging in Antioch Tomorrow (8/14/12)

Elevated WNV Risk in Brentwood; Fogging Tonight (8/6/12)

Brentwood Still Hotspot with Infected Mosquitoes; Fogging Planned (7/30/12)

More West Nile Mosquitoes and Fogging in Brentwood (7/23/12)

Birds Positive for West Nile Virus in Pleasant Hill and Knightsen (7/17/12)

Mosquitoes and Birds Positive for West Nile Virus in Brentwood (7/12/12)

National Mosquito Control Awareness Week (6/26/12)

Walnut Creek Dead Bird Positive for West Nile Virus (6/14/12)

Mosquito District Mourns Passage of Nancy Brownfield, Trustee (5/17/12)

"Mosquito Control Matters" Video Earns Contra Costa Mosquito & Vector Control District Two Awards (5/8/12)

First West Nile Virus Positive Bird of 2012 Confirmed - West Nile Virus Season Begins Early For Contra Costa County (4/12/12)

West Nile Virus Season Still Going Strong With More Infected Birds and Mosquitoes (10/18/11)

Third Human Case of West Nile Virus and Another Virus-Positive Bird in Contra Costa County (10/11/11)

Second Human Case of West Nile Virus and More Virus-Positive Birds and Mosquitoes in Contra Costa County (10/7/11)

Contra Costa Mosquito Control Investigates West Nile Virus Hotspots And Addresses Nuisance Mosquitoes In Oakley (9/23/11)

More Infected Birds Found - Residents Help Find Virus Hot Spots - REVISED (9/20/11)

West Nile Virus Risk Continues - More Mosquitoes and Birds Infected (9/12/11)

West Nile Virus Risk Increases - Mosquitoes Infected (9/6/11)

More Birds Test Positive For West Nile Virus (9/1/11)

Oakley Mosquitoes Positive For West Nile Virus (8-19-11)

First Detection of West Nile Virus in 2011 Found in Walnut Creek Dead Bird (7-1-11)

Contra Costa Mosquito & Vector Control District Wins International Award For Website (11-15-10)

Knightsen chicken, Walnut Creek bird test positive for West Nile Virus (10-11-10)

Three people, two birds infected with West Nile Virus in Contra Costa County (10-4-10)

More West Nile Virus activity in east county (9-28-10)

First chickens, more mosquitoes positive for West Nile Virus in East county (9-20-10)

Mosquitoes test positive For West Nile Virus in Oakley (9-15-10)

Contra Costa Mosquito & Vector Control District Rolls Out New Website (9-10-10)

West Nile Virus found in birds from Oakley & Brentwood (8-24-10)

West Nile Virus found in mosquitoes and bird from Oakley (8-11-10)

Record cool weather keeps West Nile virus activity below transmission levels (8-5-10)

Public urged to report dead birds to help control West Nile virus (6-8-10)

West Nile virus kills more birds, squirrel in Contra Costa County (10-14-09)

Adult mosquito fogging Wednesday evening in Martinez (10-5-09)

Adult mosquito fogging Tuesday evening in Antioch and Brentwood (9-28-09) 

Adult mosquito fogging Tuesday morning in Byron and Bethel Island (9-24-09) 

Elevated West Nile virus risk in Brentwood (9-22-09) 

Adult mosquito fogging Tuesday evening in Brentwood and Martinez (9-21-09) 

Adult mosquito fogging Tuesday evening in Byron, Discovery Bay and Martinez (9-14-09)   

More West Nile virus activity:  Three dead birds and a chicken confirmed positive for the virus in Contra Costa County (9-14-09)

Adult mosquito fogging Wednesday evening at Holland Tract - East of Oakley (8-4-09) - Cancelled