PROVO — A 79-year-old Springville man has died from severe complications caused by West Nile virus, health officials announced Tuesday.

Scott Gottfredson Orrock died Sunday morning at Utah Valley Regional Medical Center, becoming Utah's second West Nile virus-related death. A 72-year-old Uintah County woman died in September 2005 from the mosquito-borne virus.

State and Utah County health officials learned Monday afternoon that inflammation of Orrock's brain was the result of West Nile virus, said Lance Madigan, Utah County Health Department spokesman.

Orrock's wife, Dawn, said she suspects her husband was bitten by a mosquito and infected with the virus while sitting on the deck in the yard of their Springville home in late July.

"We were having a family gathering, and we noticed there were a lot of mosquitoes out there," she said.

Orrock began feeling sick on Aug. 3 and was hospitalized Aug. 9 with severe encephalitis — an inflammation of the brain caused by a viral infection. A late-July bite would fit the time frame of West Nile virus, which has an incubation period of four to 10 days.

Utah County has been hit hard with West Nile virus this year. Fifteen of the state's 23 confirmed human cases — including Sunday's death — have been found inside the county's borders.

"We've got a disproportionate share," Madigan said of Utah County, "but we've also got that great big breeding ground called Utah Lake."

The freshwater lake attracts a lot of birds, which can carry the virus, and along the shoreline there are many areas of standing water — "mosquito-growing areas," said Dr. Joseph Miner, executive director of the Utah County Health Department.

Utah County also has a lot of people — nearly 450,000, according to U.S. Census Bureau estimates — for mosquitoes to feed on.

Mosquitoes will migrate 12 to 15 miles from where they hatch, Miner said, putting a lot of people at risk.

"The lake is so central in the county," he said. "If you go 12 to 15 miles from any edge of the lake, you pretty well cover most of the populated area of the county."

Utah County, which had 15 human cases of West Nile virus in 2005, increased its mosquito-abatement efforts this year in anticipation of another heavy mosquito season.

Mosquito abatement crews have covered more than 50,000 acres in the county with aerial spraying. They've also used land vehicles for nightly fogging in problem areas near the lake.

The fogging is done to "create a buffer zone between our known mosquito breeding habitat and our residential and recreational areas," said Bob Mower, Utah County mosquito abatement director.