Contra Costa Mosquito & Vector Control

FOR IMMEDIATE RELEASE     -     August 14, 2014

Contact: Deborah Bass
               Public Affairs Mgr.

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

For human cases, please contact Contra Costa Health Services at 888-959-9911


Fogging planned in two different agricultural areas; more dead birds infected


CONCORD, CALIFORNIA - - The Contra Costa Mosquito & Vector Control District confirmed today that a group of mosquitoes from Discovery Bay and three dead birds, one each from Brentwood, Concord, and Discovery Bay tested positive for West Nile virus. All 2014 West Nile virus activity and locations can be found on the District's website.


Due to the high number of mosquitoes and the detection of West Nile virus, fogging for adult mosquitoes is scheduled in an agricultural area of Discovery Bay this evening, Thursday, August 14 from 7:45 p.m. to 11:30 p.m., weather permitting. If the weather does not permit fogging, it will be rescheduled for the evening of Friday, August 15 from 7:45 p.m. to 11:30 p.m., weather permitting. 

Fogging for adult mosquitoes is also scheduled in agricultural areas on Jersey and Bethel Islands for high populations of aggressive, day-biting mosquitoes. West Nile virus has not been detected in these areas at this time. Fogging will take place the morning of Friday, August 15 from 4:30 a.m. to 7:30 a.m., weather permitting. If the weather does not permit fogging at that time, it will be rescheduled for the morning of Saturday, August 16 from 4:30 a.m. to 7:30 a.m., weather permitting. 

Contra Costa County is home to 23 species of mosquitoes which require different habitats, prefer different hosts and biting times, and may or may not transmit a variety of diseases.


 "Each mosquito is unique and we have 23 different kinds," said the District's Public Affairs Manager Deborah Bass. "Each species has very specific attributes, such as the distance they fly to get a blood meal. Some will fly up to 20 miles and some stay within several hundred yards of their water source. Also, some can transmit disease, and some can't," she said.   


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 lives without water.
  • Defend yourself against mosquitoes by 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. 
  • Report dead birds to the state hotline: 1-877-968-2473. All reports are crucial, even if the bird does not meet criteria for testing.

Since 2005, 48 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 are grossly underreported. For 2014, a total of nine groups of mosquitoes, seven chickens and 26 dead birds 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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