CONCORD, CALIFORNIA - The Contra Costa Mosquito & Vector Control District (District) reports the first dead bird of the year has tested positive for West Nile virus (WNV) in Contra Costa County. The dead bird, an American crow, was picked up in an area of Brentwood close to Discovery Bay.

Certain birds carry WNV. Once a mosquito bites an infected bird, the mosquito can become infected. Mosquitoes can spread the virus when they bite another bird or person. To reduce the risk of WNV, the District recommends Contra Costa County residents report dead birds because dead birds are often the first sign of WNV in a particular location.

WNV can grow more efficiently when temperatures are consistently above 55 degrees. With hot daytime and warm overnight temperatures in the forecast, the District advises County residents to take steps to reduce the risk of WNV by avoiding mosquito bites.

"Infected mosquitoes can spread West Nile virus to people through a single mosquito bite, but fortunately, the virus is easily preventable. With temperatures on the rise over the next several days, it's important that Contra Costa County residents take precautions to avoid mosquito bites by using an effective insect repellent when outdoors, particularly around dawn and dusk. Wear long-sleeve shirts and long pants to reduce the amount of exposed skin that can be bitten. And avoid being outdoors where mosquitoes are present, if possible," said Steve Schutz, Ph.D., Scientific Program Manager.

Other ways to reduce the risk of mosquitoes is to dump out any amount of standing water because mosquitoes can develop from egg to adult in something as small as a bottle cap full of water. And make sure window screens do not have rips or tears and fit properly in openings.

According to the Centers for Disease Control and Prevention (CDC) when used as directed, Environmental Protection Agency (EPA)-registered insect repellents are proven safe and effective. The District recommends using EPA-registered insect repellents with one of the following active ingredients:
  • DEET
  • Picaridin
  • Oil of Lemon Eucalyptus.

Always follow the instructions on the label when using insect repellent.

Contra Costa County residents can report dead birds by phone at (877) WNV-BIRD (968-2473) or online. County residents can also request mosquito service for residential property by calling (925) 685-9301 or online.

Since 2005, 75 people in Contra Costa County have been diagnosed with West Nile virus. In 2006, two people died from the disease. For human case information, please visit the California Department of Public Health Vector-Borne Disease Section online.
 
Contra Costa Mosquito & Vector Control District, an independent special district and public health agency, is located at 155 Mason Circle in Concord.