West Nile Virus Mosquitoes Found in Sunnyvale and Santa Clara

Targeted ground mosquito control treatment scheduled for Monday, August 30 in limited areas within Sunnyvale and Santa Clara

SANTA CLARA COUNTY, CALIF. – The County of Santa Clara Vector Control District has confirmed West Nile virus (WNV) positive tests in adult mosquitoes collected from portions of the 94086, 94087, and 95051 ZIP codes that include part of Sunnyvale and Santa Clara. As a result, a truck-mounted adult mosquito control treatment has been scheduled in the area to prevent human cases of WNV. Weather permitting, the ground operations are scheduled for approximately 10 p.m. on Monday, August 30, and will conclude a few hours later. The District is adhering to all recommendations from the Centers for Diseases Control and the County of Santa Clara Public Health Department regarding the Coronavirus (COVID-19) and will be conducting the treatment in accordance with those guidelines.

Door hangers notifying the public of the scheduled mosquito treatment will be placed in neighborhoods beginning Friday, August 27. Notice is also being sent directly to the public in the treatment ZIP codes through AlertSCC, and to those who subscribe to Nextdoor neighborhood networks and our Mailchimp notifications. General notice is also being provided on various social media platforms, including Facebook, Instagram, and Twitter (@SCCVCD).

Vector Control staff will be available to answer any questions from the public, Monday – Friday, at the dedicated West Nile Virus Hotline at (408) 282-3114, from 7:30 a.m. to 4:30 p.m. Questions can also be submitted by email to [email protected].

The specific details of the operational areas are:

Treatment date:  Monday, August 30, around 10 p.m., for approximately three hours

Supervisorial Districts: District 3, 4, and 5
Cities: Sunnyvale and Santa Clara

Centered at: Sunken Garden Terrace and S. Wolfe Road

Bordered by:

  • North – Old San Francisco Road, Reed Avenue, Cassia Way, Lily Avenue, Orchid Drive, and Poinciana Drive. 
  • East – Starbush Drive, Tamarack Lane, Halford Avenue, and Thunderbird Avenue.
  • South – Burnley Way, Lillick Drive, Dunford Way, Marion Way, Carlisle Way, E. Fremont Avenue, and Duncardine Way.
  • West –  Flicker Way, Floyd Avenue, Manet Drive, Remington Drive, and S. Fair Oaks Avenue. 

Treatment ZIP codes: Part of 94086, 94087, and 95051 

Interactive map at: https://arcg.is/1rWanP

There is no need to relocate during the adult mosquito treatment. Those who wish to minimize exposure for family members or pets may close windows and remain inside during the scheduled time period, which typically lasts three hours. Individuals who have chemical sensitivities may want to consult their physicians. All control treatments utilized are approved by the Federal and State Environmental Protection Agencies and are widely used by Vector Control agencies throughout California. 

Health Effects of West Nile Virus
Since the arrival of West Nile virus to California in 2003, 7,360 people across the State have contracted the disease; 339 of those cases were fatal. In 2020, there was one human WNV related fatality; 2015 was a record year for fatalities in the state with 55 deaths.

WNV infection does not cause symptoms in most people; however, for some individuals it can cause fever, headache, body aches and, in severe cases, significant neurological damage or death. Adults older than 50 years and individuals with certain chronic medical conditions such as diabetes, high blood pressure, cancer, and kidney disease are most at risk for serious complications.  

The public can play an important role in preventing the spread of West Nile virus. The following are some key prevention measures.

On your property:
•    DRAIN or DUMP standing water weekly. Mosquitoes lay eggs in stagnant water. 
•    Drain, remove or turn over anything that can hold water, such as flowerpots, planter bases, bird baths, toys, cans, rain gutters, pet dishes, buckets, and old tires. Fix leaky water faucets and sprinklers.
•    Screens on doors and windows should be tight-fitting and in good condition.
•    Do not let your swimming pool water fall below the pump circulation area. Free mosquitofish placement can be requested online at www.sccvector.org for placement in neglected pools or ornamental ponds.

Outdoor Activities:
•    Limit outdoor activities during DUSK and DAWN to prevent mosquito bites. Those are the times when the mosquitoes that transmit WNV are most active.  
•    If you need to go outside in an area where mosquitoes are active
          o    Dress in long sleeve shirts and long pants, preferably in light colors.
          o    Apply insect repellent approved by the Environmental Protection Agency, following label instructions.

Contact the County of Santa Clara Vector Control District if you are being bothered by mosquitoes or know of a potential mosquito-breeding source. For free assistance with mosquito control or other vectors, residents can contact the District office main line at (408) 918-4770 or fill out a service request online at www.sccvector.org.




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The County of Santa Clara government serves a diverse, multi-cultural population of 1.9 million residents in Santa Clara County, California, making it more populous than 14 states in the U.S. The County provides essential services to its residents, including public health protection, environmental stewardship, medical services through the County of Santa Clara Health System, child and adult protection services, homelessness prevention and solutions, roads, park services, libraries, emergency response to disasters, protection of minority communities and those under threat, access to a fair criminal justice system, and many other public benefits.


Media Contact: Beverly Perez, County of Santa Clara Vector Control District, (408) 210-5774



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