The Santa Clara County Vector Control District plans mosquito fogging treatment late Thursday night after recently confirming that adult mosquitoes tested positive for West Nile virus in the area.

The mosquitoes were found in the 94024 and 94040 ZIP code areas of the cities of Los Altos, Los Altos Hills, Mountain View, and nearby unincorporated areas.

Weather permitting, the ground fogging in those targeted areas to prevent people from getting infected is scheduled for 11 p.m. Thursday and will last several hours.

The fogging area is generally bordered by Rosita Avenue, Glen Alto Drive, Arboleda Drive, Cuesta Drive, and Eunice Avenue on the north; Campbell Avenue, La Prenda Road, Quinnhill Road, and Casa Mia Way on the west; Truman Avenue, Marlbarough Avenue, Wessex Avenue, Austin Avenue, and Grant Road on the east; and Highway 280 and Saint Joseph Avenue on the south.

A map can be viewed at http://goo.gl/maps/uoyRA.

Scott Bourdon, director of the Department of Environmental Health, said that while the county is seeing a slow start to the West Nile virus season this year, the detection of the virus in mosquitoes (in this case one in 75 mosquitoes were infected) represents a direct risk of human infection.

"Control of infected adult mosquitoes is an essential component of preventing human cases of West Nile virus and other mosquito-borne encephalitis," said Bourdon in a statement.

Information packets will be distributed in the fogging area notifying residents about the plan. As an added convenience, on Wednesday and Thursday, the county's Vector Control District staff will be available from 7:30 a.m. to 7 p.m. through a dedicated phone line/voicemail at 1-800-314-2427 to answer questions.

Transmitted by mosquito bites, West Nile virus causes mild to severe flu-like symptoms such as fever, headache, body aches, and, in severe cases, significant neurological damage or even death. Elderly residents and those with compromised immune systems are most susceptible.

Since 2003, when West Nile virus arrived in California, 3,146 people have contracted the disease, of which 110 cases were fatal. So far this year, 11 cases have been reported statewide, with one fatality. Last season, the county's Vector Control District conducted four fogging operations, and one non-fatal human case occurred near a West Nile virus hot spot.

José Colomé, the county's Vector Control District resources specialist, stressed the importance for residents to take precautions to avoid being bitten by mosquitoes whenever they're outdoors, especially during dusk and dawn. He said people can also help by draining standing water and reporting other sources of mosquito breeding, such as neglected swimming pools,

Residents can visit the district's website at www.sccVector.org to view a map of the fogging zone, read the latest alerts about West Nile virus activity in the county, request advice or services, or to subscribe for fogging announcements.

For free assistance on mosquito control, West Nile virus, or other vectors, county residents can contact the district office by calling 408-918-4770 or 1-800-675-1155 or fill out a service request online at www.sccVector.org.

TAKE THESE MEASURES AGAINST MOSQUITO BITES
At home:
Drain or dump standing water weekly since this is where mosquitoes lay eggs. Check items such as flowerpots and planter bases, toys, cans, leaky water faucets and sprinklers, rain gutters, buckets, pools, ponds, and old tires.
Make sure your doors and windows have tight-fitting screens.
Outdoors:
Limit outdoor activities during dusk and dawn to prevent mosquito bites. Those are the times when the mosquitoes that transmit West Nile virus are most active.
If you need to go outside at dusk or dawn, or when in an area where mosquitoes are active:
Dress in long sleeve shirts and long pants, preferably light-colored. 
Apply insect repellent following label instructions.
Always contact the Santa Clara County Vector Control District if you're being bothered by mosquitoes or know of a potential mosquito-breeding source.
The district's laboratory conducts in-house testing for West Nile virus and other vector-borne diseases throughout the year. County residents are asked to report crows, jays, or birds of prey that have been dead for less than 48 hours and do not appear to have died because of an injury. Anyone who finds those birds should call the California West Nile virus hotline at 1-877-968-2473 (1-877-WNV-BIRD) or to go at www.westnile.ca.gov.
Source: Santa Clara County Vector Control District