News Release
For Immediate Release   -   July 19 , 2018
Contact: Nola Woods, Public Affairs Director

Direct:  925.771.6158
Cell:  925.250.6502

District urges residents to take precautions to reduce the risk of West Nile Virus

CONCORD, CALIFORNIA - The Contra Costa Mosquito & Vector Control District reports mosquitoes from two locations in Contra Costa County have tested positive for West Nile virus. 

The infected mosquitoes were caught in traps in Discovery Bay and an agricultural area east of Brentwood. The District uses this information to direct prevention and control efforts within the vicinity.  

The confirmation of infected mosquitoes comes less than one week after the District confirmed chickens tested positive for antibodies against West Nile virus near Knightsen.   

"We are seeing a typical summer pattern where West Nile virus activity starts in the warmer areas of the Central Valley and gradually moves west into Contra Costa County as our weather warms up." said  Steve Schutz, Ph.D., s cientific programs manager.

Hot weather speeds both virus growth and mosquito development, and serves as an important reminder to residents to defend themselves against West Nile virus and other mosquito-borne illnesses.

"Detection of virus in mosquitoes and sentinel chickens is an indication that the risk of human cases is increasing, so people spending time outdoors should take precautions to prevent mosquito bites," said Schutz. 

The District encourages residents to reduce their risk of contracting  West Nile virus and other mosquito-borne diseases by: 
  • Defending yourself - use repellents containing DEET, Picaridin, or Oil of Lemon Eucalyptus.
  • Avoiding the outdoors when mosquitoes are present, typically dawn and dusk.
  • Dumping or draining standing water to prevent mosquitoes. Most mosquitoes can't start their lives without water.
The District also urges the public to report dead birds.

"Usually we detect West Nile virus in dead birds first, but this year we've been getting very few dead bird reports from the public, so we haven't had many to test," said Schutz. 

Ravens, jays and crows can be susceptible to the virus, and may die if infected.  The District asks residents who find a dead bird to report it to the statewide  West Nile Virus Hotline online  or by calling (877) WNV-BIRD (968-2473). Dead birds can be important evidence of West Nile virus in the county. 

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For a list of Contra Costa County's  2018 West Nile virus activity and locations, visit the  District's website

Since 2005, 63 Contra Costa County residents have been diagnosed with West Nile virus. In 200 6, two people died from the disease. For current human case information, please contact Contra Costa Health Services at 888-959-9911.

Contra Costa Mosquito & Vector Control District, an independent special district and public health agency, is located at 155 Mason Circle in Concord. Contact the District to report mosquito problems online or at (925) 685-9301. Visit the office between 8:00 a.m. and 4:30 p.m. to get FREE mosquitofish for ornamental ponds, horse troughs or neglected swimming pools.
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Contra Costa Mosquito & Vector Control