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West Nile Virus

West Nile virus is an infection of birds that is transmitted by mosquitoes. Occasionally, humans and animals are infected when bitten by an infected mosquito. West Nile virus tends to be seasonal, beginning in the early summer and continuing through fall. In humans, it causes mild to severe flulike symptoms, including fever, headache and body ache. Though rare, it can be fatal for the elderly and people with compromised immune systems.

What You Can Do

Protect your house, septic system and use insect repellents when outside. It is also helpful to report dead birds and squirrels. To report a dead bird or squirrel in California, submit a web-based form or call 1-877-968-2473.

About West Nile virus

Important numbers

  • Contra Costa Mosquito and Vector Control District - 925-771-6196
  • Report dead birds and squirrels - 1-877-968-2473
  • Contra Costa Health Information - 1-888-959-9911 or 211



Latest News

» Media Release/Advisory from Contra Costa Mosquito & Vector Control District




Content provided by the Public Health Division of Contra Costa Health Services.

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