Mosquitoes found in Campbell, Los Gatos, Monte Sereno and San Jose tested positive for West Nile Virus, county officials warned Monday.

That means residents of those areas should ready themselves for another round of pesticide fogging by the Santa Clara County Vector Control District.

A ground fogging is set for 11pm Tuesday, weather permitting, around Los Gatos Boulevard and Lark Avenue. It should last for several hours. Another is scheduled for an area bordered by White Oaks Road to the north, Charlotte Avenue to the east, Winchester Boulevard west and Blossom Hill Road to the south.

Click here to see a live map of the fogging zones.

West Nile Virus causes severe flu-like symptoms, including fever, headache, body aches and, rarely, brain damage and death. Children and the elderly are most at risk of contracting the illness. Since first recorded in California in 2003, 4,006 people statewide have contracted the disease and 145 have died from it.

“There is no cure for the West Nile Virus disease, only prevention,” Acting District Manager Russ Parman said. “Draining standing water around your house reduces breeding sites for mosquitoes and helps reduce risk for human infections.”

County officials handed out information packets to residents who live in the targeted fogging areas. Staff will be available to take questions from residents from 7:30am to 7pm Tuesday on a dedicated phone line: 800.314.2427.

“Residents can play a strategic role in preventing the spread of West Nile Virus,” Parman said. “It is important to remain vigilant by taking practical steps to eliminate mosquito breeding areas.”

Some of those steps include draining or pumping water where mosquitos could lay eggs. Clean birdbaths and pet water dishes regularly. Make sure doors and windows have tight screens.