West Nile Virus

West Nile (WN) virus has emerged in recent years in some regions of Europe and North America, presenting a threat to the health of people and animals. People become infected when bitten by mosquitoes infected with West Nile virus. Mosquitoes become infected from biting live birds that have the virus. For more background about the symptoms, transmission and history of West Nile, consult our Frequently Asked Questions.

What You Can Do

Dead birds can carry the West Nile Virus. To report a dead bird in California, submit a web-based form or call toll free 1-877-WNV-BIRD (877-968-2473). Crows, ravens, jays, magpies, hawks, sparrows and finches are being tested. Dead squirrels can also be reported to that line.

Here are some things you can do to prevent the spread of this dangerous disease:

• Eliminate standing water from collecting on your property. Mosquitoes can breed in any puddle or standing water that lasts for more than four days.
• Dispose of, turn upside down, or regularly empty any metal cans, plastic containers, ceramic pots, and other water holding containers on your property. Pay special attention to discarded tires, a common place for mosquitoes to breed.
• Do not allow water to stagnate in birdbaths. Change it every three to four days.
• Clean clogged roof gutters of leaves and debris that prevent drainage of rainwater.
• Aerate ornamental ponds or stock them with fish. In Contra Costa County free mosquitofish can be obtained by calling Contra Costa Mosquito & Vector control at 925-685-9301.
• Limit the amount of time spent outdoors at dawn and dusk, or at other times when mosquitoes are active. Particularly during mosquito season, May to October.
• Wear long-sleeved shirts and long pants when outdoors.
• Use insect repellent containing the ingredient DEET - Use according to manufacturer's label.
• Fix any holes in screens and make sure they are tightly attached to the doors and windows.

Important numbers

• For Health Information - Contra Costa Health Services 1-888-959-9911
• For Mosquito Information - Contra Costa Mosquito and Vector Control District 925-685-9301

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