West Nile virus detected in dead bird in Menlo Park - First detection in 2026
FOR IMMEDIATE RELEASE
Contact: Rachel Curtis-Robles, PhD
Communications Director
650-344-8592
West Nile virus detected in dead bird in Menlo Park - First detection in 2026
Burlingame, CA (June 24, 2026) - The San Mateo County Mosquito and Vector Control District reports a dead American Crow collected from Menlo Park has tested positive for West Nile virus. This is the first detection of West Nile virus activity in San Mateo County in 2026.
Certain birds, including crows, jays, ravens, and robins, may carry West Nile virus. When a mosquito bites an infected bird, the mosquito can become infected. Infected mosquitoes can then pass the virus on to people or other animals that they bite. Reports of dead birds are often the first sign of West Nile virus in an area.
In response to this detection, District staff are setting additional mosquito traps in the neighborhoods near where the dead bird was found to determine whether mosquitoes carrying West Nile virus are in the area. While District staff routinely inspect and treat mosquito breeding sources throughout the County to reduce the number of biting mosquitoes that could become infected and transmit West Nile virus, inspection and treatment efforts in the immediate area of the positive bird are being increased.
Residents should keep in mind that it only takes a small amount of water to produce mosquitoes. Follow these simple steps to reduce the risk of mosquitoes and the diseases they transmit:
- Dump standing water at least once a week, including flowerpots and saucers, old tires, buckets, pet dishes, clogged rain gutters, and trash cans.
- When outside and mosquitoes are active, apply insect repellent containing an active ingredient registered with the Environmental Protection Agency – such as DEET, picaridin, oil of lemon eucalyptus, or IR3535 – according to label instructions.
- Wear long sleeves and pants, especially if outside at dawn and dusk when mosquitoes are most active.
- Install screens on windows and doors, and keep them in good repair to keep mosquitoes out.
- Report dead birds to the statewide West Nile Virus Call Center by phone at 1-877-WNV-BIRD (1-877-968-2473) or online. Not all birds can be tested, but all reports help the District identify potential risk areas for West Nile virus.
If you are being bitten by mosquitoes while on your property, request a visit from District staff. For assistance with a mosquito problem in San Mateo County, contact the District at 650-344-8592. For more information about West Nile virus and District services, go to the District’s website at http://www.smcmvcd.org/.
The San Mateo County Mosquito and Vector Control District’s programs and services are funded through property taxes and benefit assessments and are provided to all residents in San Mateo County at no additional charge.
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About the San Mateo County Mosquito & Vector Control District: We are an independent special government district that is focused on protecting the public health of the residents of San Mateo County through a science-based program of integrated vector management that is responsive to the community. The District delivers specific services to residents and businesses under the guidance of a Board of Trustees comprising representatives from each of the 20 cities in San Mateo County and the County Board of Supervisors.
