West Nile virus in Lake County

West Nile virus has turned up in Lake County.

Three cases of the virus - affecting one woman and two horses - have been confirmed by the county's Health Department.

Mosquitoes in the Ninepipe area of Lake County also are testing positive for the virus.

The Lake County woman diagnosed with West Nile is the state's fourth human case this year.

Elton Mosher, the state's West Nile surveillance specialist, said it's likely the woman was bitten by an infected mosquito in Missouri.

He said the woman, who is in her 50s, did not require hospitalization and is expected to make a full recovery. The other West Nile cases in the state this year were in Richland, Cascade and Big Horn counties.

As of Aug. 29, Flathead County had no cases of West Nile virus and no mosquitoes testing positive.

Flathead County Mosquito Control Coordinator Bruce Gunderson said that compared to this time last year, mosquito numbers are way down. Traps that were catching 20 mosquitos a week last year are turning up empty or with just three or four insects now.

"We're dodging the bullet," Gunderson said.

The recent numbers come as a surprise after two massive hatches in early summer set the stage for a summer plagued by mosquitoes. Cold nights and moderate daytime high temperatures have helped keep the population in check recently. The first fall frost typically wipes out the mosquito population.

West Nile virus is a potentially serious illness with symptoms ranging from fever and headache to muscle weakness and coma. About 80 percent of people infected with the virus will not show any symptoms. People over age of 50 are more likely to develop serious symptoms.

The virus is most often spread by the bite of an infected mosquito. Only certain types of mosquitoes are capable of being West Nile virus carriers. The virus is not spread through casual human contact such as touching or kissing.

To prevent infection from West Nile virus, use insect repellents containing DEET, wear long sleeves and pants, remove areas of standing water and avoid outdoor activity at dusk and dawn.

The Associated Press contributed to this story.