Positive West Nile Virus Mosquitoes Found in Portions of Cupertino

Targeted adult mosquito control treatment scheduled for Thursday, August 11 in a limited area within Cupertino

SANTA CLARA COUNTY, CALIF. The County of Santa Clara Vector Control District has confirmed the presence of West Nile virus-positive mosquitoes in a small area of Cupertino (ZIP Code 95014). Weather permitting, this area will be treated to reduce adult mosquito populations with the use of truck-mounted equipment on Thursday, August 11, starting around 10 p.m., and concluding a few hours later.

The District’s mosquito management program largely focuses on preventing mosquitoes from reaching adulthood by proactively targeting immature stages of mosquitoes (eggs, larvae, and pupae). When a mosquito with West Nile Virus (WNV) is detected, however, the District takes the added step of conducting a mosquito control treatment to reduce the adult mosquito population in the area, which reduces the risk of a WNV-human infection.

It is normal to see an increase in West Nile virus during the summer because mosquitoes thrive in hot weather. The District has a dedicated surveillance program to detect the presence of diseases like West Nile virus, St. Louis encephalitis, and western equine encephalitis, all of which are transmitted through the bite of infected mosquitoes. The data collected through surveillance is used to predict locations that are more likely to have these disease-transmitting mosquitoes.

The District has been conducting truck-mounted treatments regularly since 2003 to successfully reduce WNV-transmitting mosquito populations. The District will be adhering to requirements and recommendations from the County of Santa Clara Public Health Department for COVID-19.

Notice is being sent directly to the public in the treatment ZIP code through AlertSCC and to those who subscribe to Nextdoor neighborhood networks. General notice is being provided on various social media platforms – including Facebook, Instagram and Twitter (@SCCVCD) – and to those subscribed to the District’s mosquito treatment notifications.

Vector Control staff will be available to answer any questions from the public, Monday–Friday, on the dedicated West Nile Virus Hotline at (408) 282-3114, from 7:30 a.m. to 4:00 p.m. Questions can also be submitted by email to [email protected].

The specific details of the operational areas are:

Treatment date: Thursday, August 11, around 10 p.m., for approximately four hours

Supervisorial Districts: District 5

Cities: Cupertino

Map of the treatment area

Centered at: Stevens Creek Boulevard and N. Stelling Road

Bordered by:

  • North – Phar Lap Drive, Kimberley Drive, Mary Avenue, N. De Anza Boulevard, Randy Lane, Plum Tree Lane, and N. Blaney Avenue
  • East – Homestead Road, Pendleton Avenue, Pocatello Avenue, Stevens Creek Boulevard, Lucille Avenue, Merritt Drive, and Forest Avenue
  • South – S. Blaney Avenue, Farallone Drive, Westlynn Way, Tuscany Place, Bubb Road, Linda Vista Drive, McClellan Road, and Byrne Avenue
  • West – Somerset Drive, Pacifica Drive, John Drive, Bollinger Road, Heatherwood Drive, Creekline Drive, Columbus Avenue, and Hyannisport Drive

ZIP Code affected: Part of 95014

Interactive map: https://arcg.is/0j8vWf0

There is no need to relocate during the treatment. Mosquito treatments pose minimal risk to people, pets, animals, and the environment when applied by a licensed vector control professional following label instructions. Those who would like to take extra precautions can keep family and pets inside during the treatment, with windows and doors shut during the duration of the control treatment (approximately four hours). By sunrise, the insecticide will quickly break down with the sunlight. Since the District applies insecticides at the ultra-low volume (ULV), individuals aren’t likely to breathe or touch anything that has enough insecticide on it to be harmful. Those with chemical sensitivities may want to consult their physicians for additional recommendations. All control materials utilized in our mosquito control program are approved by the Federal and State Environmental Protection Agencies and are widely used by vector control agencies throughout California.

For more information on the products used for this mosquito control treatment, including the safety data sheet, insecticide label, and a list of our most frequently asked questions, please visit our website at www.sccvector.org. For additional information on adulticides, visit the Centers for Disease Control and Prevention’s website at www.cdc.gov. For information on West Nile virus activity in California, please visit www.westnile.ca.gov.

Health Effects of West Nile Virus

Since West Nile virus arrived in California in 2003, 7,474 people across the state have contracted the disease; 359 of those cases were fatal. In 2021, there were 12 human WNV-related deaths; 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 assist in preventing the spread of West Nile virus by taking the following prevention measures.

On your property:

  • Dump or drain standing water weekly. Mosquitoes need stagnant water to lay their eggs and spend three out of four life stages in 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. For more information on water conservation and mosquito prevention, visit bit.ly/nowaternomosquitoes.
  • 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 can be requested online at www.sccvector.org for placement in neglected pools or ornamental ponds. For more information on our mosquitofish program, please visit www.sccvector.org/mosquitofish.

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:
    • Dress in long-sleeve shirts and long pants, preferably in light colors.
    • Apply insect repellent approved by the Environmental Protection Agency, following label instructions. For more information on mosquitoes, visit www.sccvector.org/mosquitoes.

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, multicultural population of 1.9 million residents in Santa Clara County, Calif., 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.

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Media Contact: Vector Control District, [email protected](408) 918-4770

Posted: August 9, 2022


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