CONCORD, CALIFORNIA - - The Contra Costa Mosquito & Vector Control District confirmed today that three more chickens from Holland Tract, an area near Brentwood, and one dead bird each from Bethel Island and Walnut Creek tested positive for West Nile virus.

"We're responsible for protecting public health across 736 square miles," said the District's Public Affairs Manager Deborah Bass. "With a plethora of backyard containers including the notorious neglected swimming pools invisible to us, as well as a host of other mosquito sources, we use a variety of tools to monitor for and treat mosquitoes. Overall, chickens and dead birds serve as early warning systems that alert us to virus transmission. We can then scour the immediate area for mosquitoes and treat them accordingly."

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.   

• 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 www.ContraCostaMosquito.com  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, 47 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 one group of mosquitoes, four chicken and 11 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.