San Ramon Bird Tests Positive For West Nile Virus: Mosquito District

SAN RAMON, CA — The first avian case of West Nile virus in 2025 was reported July 21 in San Ramon, according to the Contra Contra Mosquito and Vector Control District.

Testing confirmed that a California scrub jay in San Ramon was infected with West Nile virus. Infected birds are often the first sign of West Nile virus, and cases have already been reported in Alameda and Santa Clara counties earlier this year, according to the district.

“We typically start seeing West Nile-positive birds and mosquitoes in Contra Costa County around this time of year,” District Scientific Program Steve Schutz, said in a statement. “Our neighboring counties have been reporting positive samples for several weeks now. As the weather warms up, the risk of human cases will continue to increase.”

To reduce the risk of mosquitos, the district recommend dumping out standing water at least once a week, and using EPA-registered insect repellents with one of the following ingredients:

• DEET
• Picaridin
• The repellent version of Oil of Lemon Eucalyptus
• IR3535

Residents should also report dead birds to 877-968-2473or online. Contra Costa County residents can also request mosquito service for residential properties online, or by calling 925-685-9301.