MOSES LAKE — Grant County Health District reported Grant County’s first confirmed case of West Nile virus in a human Friday.

The patient is a 50-year-old Moses Lake woman. She is not hospitalized and is recovering at home, said public information officer Theresa Fuller.

Her exact state and symptoms are unknown. The woman is believed to have contacted the virus in her backyard, Fuller said.

The district received her positive test results from the Washington State Public Health Laboratories Thursday night.

“We know it is here so we were not surprised,” Fuller said.

Ten mosquito samples and eight horses in Grant County tested positive for West Nile virus this year. Statewide confirmed cases include, 10 humans, 43 mammals, 16 birds and 336 mosquito samples, according to the Washington State Department of Health.

“The virus is mild for most people,” Fuller said. “Some may recover, not even realizing they have it.”

West Nile virus is spread to people and animals by an infected mosquito. In about 80 percent of cases, those infected do not display any symptoms, according to the health district.

Only 20 percent of infections result in symptoms, referred to as West Nile fever. Symptoms may include fever, headache, body aches, skin rash and swollen lymph glands, according to the health district.

West Nile fever is severe when it invades the nervous system, possibly causing inflammation of the brain. Less than 1 percent of patients experience severe symptoms, said Fuller.

There is no human vaccine against the virus, or any specific treatment.

Most people at risk are suffering from a weak immune system and those over 50, said Fuller.

The best preventive measures are to reduce the places mosquitoes live and breed around the home.

“Avoid giving mosquitoes a home,” Fuller said. “Avoid bites by making sure screens are repaired, wearing long-sleeves and pants and using insect repellent.”