ELLENSBURG, Wash. -- A Klickitat County man in his 50s is the state's first confirmed case of West Nile virus infection this year in a human, state health officials said Tuesday. The man is recovering.

But health officials say the confirmation is all the more reason for the public to take precautions against mosquito bites, including wearing repellent containing Deet and eliminating standing water -- prime mosquito breeding grounds.

There is no human vaccine for West Nile virus. Nor is there a cure. People with the illness need plenty of fluids and lots of rest.

Testing at the state Department of Health's Public Health Laboratories in Shoreline and at the federal Centers for Disease Control and Prevention confirmed the Klickitat man's diagnosis.

Officials believe the man was bitten by an infected mosquito in the state. He was exposed sometime in early to mid-July. It typically takes two days to two weeks before symptoms emerge.

Meanwhile, the Yakima Health District is waiting for results from samples taken from six people infected with a mosquito-borne infection. The tests will confirm whether the individuals have West Nile virus or two other types of encephalitis -- St. Louis or Western Equine. Three of those individuals remain hospitalized.

Encephalitis is inflammation of the brain, while meningitis is inflammation of the lining of the spinal cord and brain. People over age 50 have the highest risk for serious illness. The virus can be fatal.

Symptoms may include fever, headache, body aches, neck stiffness, stupor, disorientation, tremors, convulsions, muscle weakness, paralysis and coma.

West Nile virus activity in the state began earlier this year than in previous years. The virus first appeared in Yakima County five years ago.

Last year, two people in Yakima County tested positive for West Nile virus. They recovered.