West Nile virus was detected in mosquitoes collected from an area around the 94087, 95050 and 950512 zip codes in parts of Santa Clara and Sunnyvale, the Santa Clara County Vector Control District announced Monday.

The vector control district is planning a targeted treatment operation on Wednesday in an effort to prevent human cases of West Nile virus, which has resulted in 292 fatalities statewide since 2003.

The vector control district said the truck-mounted treatment will begin at 11 p.m. and last about three hours. The boundaries of the area being treated include Cabrillo, Machado, Santa Maria and Warburton avenues to the north, Long Street, Scott Boulevard, Fairfield Avenue and Robin Drive to the east, E. Homestead Road, Lehigh and Kenyon drives, Forbes and Taft avenues to the south and Swallow and Teal drives, Turnstone Way, Halford Avenue and Lawrence Expressway to the west. The map is available here.

The county vector control district said there is no need to relocate during the treatment, but those who want to limit exposure can close windows and remain inside. The chemicals used in the treatment are approved by federal and state environmental protection agencies, the county said.

West Nile, a virus reported in all U.S. states, is spread to people by mosquito bites and most people infected do not detect symptoms, according to the Centers for Disease Control and Prevention. Since the arrival of West Nile in California in 2003, there have been 6,601 people to contract the disease statewide, resulting in 292 fatal cases, according to the county.

The county vector control district said residents can help prevent the spread of West Nile Virus by doing the following:

  • Mosquitoes lay eggs in water.  Drain or dump standing water weekly.
  • Drain, remove or turn over anything that can hold water: 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.

For free assistance with mosquito control, West Nile Virus or other vectors, residents can contact the county by calling 408-918-4770 or by filling out a service request online at SCCvector.org.