What is West Nile virus?

West Nile virus (WNV) is a viral infection of birds that is transmitted from bird to bird by mosquitoes. Occasionally humans, horses, and other animals can become infected when they are bitten by an infected mosquito.   The illness it causes in humans can range from mild to very serious.

Latest Information on West Nile Virus in Contra Costa County

(From the  Contra Costa Mosquito and Vector Control District)

Resources for information on West Nile Virus

Contra Costa Mosquito and Vector Control District