So far, no West Nile in Valley

After last year's dramatic increase in Nevada's West Nile virus infections, just four human cases have been diagnosed to date, none of those in Douglas County.

The number of human cases statewide has dropped dramatically, from 68 through August 2006 to just four, through August, according to information from the Nevada State Health Division.

Mosquitoes are the primary carrier for the blood-borne disease but not one mosquito pool in Douglas County or Carson City has tested positive, according to Ron Lynch, spokesman for Douglas County Mosquito Control.

Lynch said he's still spraying standing water, but there's a lot less of it this year.

"We've sprayed Westwood a few times and we got the airplane out for the first time recently and sprayed 100 acres," he said. "But all mosquito pools are negative and the largest number of mosquitoes we get in any one pool is five.

"The mornings are cold and that's helping us too. The mosquitos aren't out and about," he said.

Martha Framsted, spokeswoman for the Nevada State Health Division, said officials there are not willing to attribute the drop in cases to this season's drier conditions.

"We think we need a few more years of data," Framsted said.

Some other areas of the country have seen a reduction in the number of cases, despite wetter weather.

July was ranked the fourth wettest on record in Iowa, where just three human cases have been diagnosed to date. The state had 37 cases last year during the season, which extends through October, according to information from the Centers for Disease Control and Prevention in Atlanta, Ga.

Historically, case numbers have dropped significantly in September and October, as cooler temperatures mark the end of the mosquito season.

Idaho, which reported 996 human cases, more than any other state in the country in 2006, has just 23 cases this year.

Framsted said she likes to think the use of preventive measures is responsible for the drop.

"People shouldn't let their guard down," she said. "It's still prudent to continue preventive measures."

Residents can help prevent spread of the disease by removing any standing water from around their homes, wearing mosquito repellent and/or protective clothing and making sure all window screens are in good repair.

Susie Vasquez can be reached at svasquez@recordcourier.com or 782-5121, ext. 211.