West Nile Virus Information

West Nile virus is a viral disease of birds that is transmitted from bird to bird by way of a mosquito bite. It can occasionally cause meningoencephalitis (inflammation of the brain and spinal cord) in susceptible people or animals that are bitten by infected mosquitoes. Most people who contract the virus will have few or no symptoms and will recover completely. About 1 in 150 people who contract the disease may develop serious complications. Elderly people are more at risk of such complications. There is currently no vaccine or specific treatment available. If you think you or a family member may have West Nile virus, please contact your physician.

West Nile Virus Questions and Answers

The Centers for Disease Control provides answers to questions regarding the mosquito-borne illness. READ MORE.


Should We Worry About West Nile Virus?

West Nile virus is dangerous. It arrived into Contra Costa County in 2004, a mere five years after it first entered the Western Hemisphere into New York in 1999. It's now endemic - established and ingrained into our environment. READ MORE.


The Importance of Reporting Dead Birds

While the Contra Costa Mosquito & Vector Control District cannot test every bird that is collected for West Nile virus, reporting them alone are crucial to our surveillance efforts. Find out why. READ MORE.


West Nile Virus Presentation (video)

Learn more about West Nile virus by watching this informative presentation. CLICK TO VIEW VIDEO.


West Nile Virus Mosquitoes of Contra Costa County

Out of the 23 species of mosquitoes found in Contra Costa County, two species are known transmitters of West Nile Virus. READ MORE.


West Nile Virus in Horses and Other Animals

Horses are susceptible to West Nile virus and about 1/3 of the horses that develop symptoms will die. READ MORE.


West Nile Virus Information for Physicians

An important resource regarding West Nile Virus specifically for physicians.READ MORE.


How YOU Can Protect Yourself

Protect yourself from mosquitoes and the diseases they transmit by practicing the District's "7 D's of mosquito prevention." READ MORE.

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