An area of San Jose will be fogged tonight as part of a mosquito eradication effort to protect against the spread of West Nile virus.

The Santa Clara County Vector Control District scheduled the 11 p.m. ground fogging after determining that a sampling of adult mosquitoes from South San Jose had tested positive for the virus.

Acting district manager Russ Parman said 1 to 3 percent of mosquitoes in the area are carrying the virus.

“West Nile virus continues to be active in mosquitoes in the southwest San Jose area, so it is important to keep the numbers of mosquitoes as low as possible,” he said in a statement.

West Nile virus is transmitted to humans by mosquitos and can cause mild to severe flu-like symptoms, such as fever, headache and body ache. In severe cases, the virus can cause significant neurological damage and even death, according to the district.

Nayer Zahiri, a vector ecologist, said the county has experienced a virus amplification since the beginning of August.

“Residents throughout Santa Clara County should avoid mosquito bites, and keep an eye out for standing water, which can harbor mosquitoes,” Zahiri said.

The area that will be fogged tonight is bordered by Hillsdale Avenue on the north; Pearl Avenue, Kenton Lane, Glenmont Drive, and Windfield Boulevard on the west; Monterey Avenue, Apple Blossom Drive, Lean Avenue, and Dunn Avenue on the east; and Curie Drive, the foothills, and Foothill Drive on the south.

Officials believe that dead birds are an early warning sign indicating the presence of the virus.

The district has a new laboratory that allows in-house testing for the virus and other vector-borne diseases throughout the year.