A three-mile area within San Jose and Campbell will be sprayed Thursday in response to mosquitoes testing positive for West Nile virus in Santa Clara County.

Officials said this will be the earliest spraying the South Bay has seen and blame it on California's severe drought.

"We've also had an unusually warm spring and summer," "Everything in the mosquito is done by temperature. The warmer it is, the faster they move."

Thursday's spraying is scheduled to begin at 11 p.m. and is expected to last a few hours in the area where Interstate 680 and Highway 17 intersect, near Valley Medical.

The Santa Clara County Vector Control District on Tuesday distributed information packets to notify residents about the fogging operation.

West Nile can cause mild to severe flu-like symptoms, such as fever, headache, body aches, and, in severe cases, significant neurological damage or even death.

Dr. Noor Tietze of the Santa Clara County Vector Control District says “this underscores the need for residents to protect themselves from mosquito bites, and to eliminate standing water on their properties.”