West Nile Virus Detected in Yuba County as Yuba City Fogging Continues

West Nile virus activity has been detected in Yuba County mosquitoes, and mosquito-control crews were scheduled to continue fogging in areas of Yuba City and nearby communities on Tuesday morning, July 28.

The Sutter-Yuba Mosquito and Vector Control District said the first 2026 detections in Yuba County came from two mosquito samples collected July 7. One sample came from the Hallwood area and the other from the Wheatland area.

What local surveillance shows

In its surveillance update dated July 24, the district reported two positive mosquito samples and one positive dead bird in Yuba County. It reported eight positive mosquito samples and one positive dead bird in Sutter County.

The district reported zero confirmed human cases in both counties as of that update. Positive mosquito samples and dead-bird findings indicate West Nile virus activity in the local environment, but they do not establish a human outbreak or mean that every resident has been exposed.

Most people infected with West Nile virus have no symptoms. Some develop fever, headache or body aches, while fewer than 1% develop severe illness that can affect the nervous system. Preventing mosquito bites remains important even when no human cases have been confirmed locally.

Where fogging was scheduled

The district’s July 27 notice scheduled Tuesday-morning operations in areas of Yuba City, Live Oak, Sutter and Tierra Buena. The work generally takes place from about 3:30 a.m. to 6:30 a.m. using pickup-mounted foggers.

Applications depend on mosquito abundance, disease activity and favorable weather conditions. The notice describes coverage in areas of the listed communities, not every neighborhood or street. Residents should check future district notices for updated schedules rather than assume that all parts of Yuba City will be treated.

How residents can reduce exposure

• Use an EPA-registered repellent containing DEET, picaridin, oil of lemon eucalyptus or IR3535, following the product label.
• Wear long sleeves, long pants and other clothing that covers exposed skin when mosquitoes are active.
• Limit outdoor activity around dawn and dusk, when mosquitoes that transmit West Nile virus may be more active.
• Keep doors and windows screened and repair damaged screens.
• Drain standing water from flowerpot saucers, buckets, tires, birdbaths and other containers around homes and businesses.

Residents can help local surveillance by reporting dead birds through the California West Nile Virus website or by calling 877-968-2473. Dead-bird reports do not confirm that a bird died from West Nile virus, but they can help public-health officials identify areas where testing and mosquito-control work may be needed.

Residents with questions can contact the Sutter-Yuba Mosquito and Vector Control District at 530-674-5456, extension 0, during weekday office hours. The district also offers email notifications about mosquito-spraying operations.

For Yuba City residents, the main takeaway is straightforward: local environmental activity has been confirmed, but no human cases were reported in Yuba or Sutter counties as of July 24. Repellent, protective clothing, screened windows and removal of standing water remain the most practical steps while the district continues monitoring and scheduled control operations.

Sources

• Sutter-Yuba Mosquito and Vector Control District WNV update
• The Sacramento Bee: West Nile virus detected in Yuba County