Contra Costa Mosquito & Vector Control

FOR IMMEDIATE RELEASE     -     August 22 , 2013

Contact: Deborah Bass
              Public Affairs Mgr.

(925) 771-6112 - office
(925) 260-4670 - mobile 


High virus activity detected; fogging for adult mosquitoes tonight in Brentwood


CONCORD, CALIFORNIA - - The Contra Costa Mosquito & Vector Control District (District) announces that nine more dead birds, four chickens, and five more mosquito samples are positive for West Nile virus. Eight of the birds are American crows and one is a Western scrub jay. Two birds were found in Antioch, two in Brentwood, three in Concord, one in Martinez and one in Walnut Creek. Three chickens from Holland Tract and one chicken from Oakley tested positive for the virus. Five virus-positive mosquito samples were trapped in Brentwood.


"We have fairly low mosquito populations throughout the county," said Steve Schutz, Ph.D, scientific program manager for the District.  "The virus activity, on the other hand, is elevated and spread out like a shotgun effect across the county with a concentration in Brentwood. Everyone should take the proper precautions against mosquito bites."


Due to the presence of virus-carrying mosquitoes and other factors in Brentwood, the District will fog for adult mosquitoes this evening. The District encourages people to sign up for automatic spray notification emails that detail in an interactive map, every street the District is planning to fog.


Birds are the reservoir for West Nile virus. The two species of mosquitoes in Contra Costa County capable of transmitting the virus prefer to feed on birds; however, people can become infected when a mosquito bites an infected bird and then a person. West Nile virus symptoms of the mild form include fever, headache, tiredness, body aches, and swollen lymph glands. While the illness can last only a few days, even healthy people have reported being sick for several weeks. West Nile virus of the severe form can be fatal.   


Residents are urged to help reduce their risk of contracting mosquito-borne diseases by following these guidelines: 

  • Dump or drain standing water. Mosquitoes can't begin their life without water.
  • Defend yourself against mosquitoes using repellents containing DEET, Picaridin, or Oil of Lemon Eucalyptus.
  • Avoid being outdoors when mosquitoes are present, typically dawn and dusk.
  • Report neglected swimming pools by calling 925-771-6195 or visiting  Anonymous calls accepted. Just one neglected pool can produce more than 1 million mosquitoes and affect people up to five miles away. 

Since 2005, 42 people in Contra Costa County have been diagnosed with West Nile virus. In 2006, two people died from the disease. Recent studies have shown that the majority of cases are not diagnosed and grossly under reported. For 2013, a total of nine groups of mosquitoes, 46 dead birds and four chickens have tested positive for the virus.  


Visit the District's website or click on these links for  current West Nile virus activity  or to  receive automatic emails for when the District fogs for adult mosquitoes.


Contra Costa Mosquito & Vector Control District, an independent special district and public health agency, is located at 155 Mason Circle in Concord. Call the District to report mosquito problems at (925) 771-6195 or visit their 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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