Two people and two horses infected with West Nile Virus in Eastern Washington

Two people in Eastern Washington tested positive for West Nile virus in the past week, the state Department of Health said Monday.

The residents are from Walla Walla and Franklin counties, and likely were infected with the mosquito-borne virus in those counties, a release from the Department of Health said. They are the first residents of the state believed to have contracted the virus from within Washington this year, according to data from the Department of Health.

Mosquitoes spread West Nile in the summer and early fall by biting, the release said. Washington typically gets a few cases of West Nile annually, usually in south-central Washington and other areas that get hot in the summer.

There were four confirmed human West Nile cases in Washington residents in 2022, but none of those people were believed to have been infected in the state, according to data from the Department of Health. Over the past few years, there have only been a few known infections from within the state annually, but there were 22 in 2015.

The two human cases follow positive tests from two horses in the region, the release said. The horses were likely infected in Grant and Benton counties. Horses can be vaccinated for West Nile, but people cannot.

While most people who test positive don’t develop symptoms, the release said about one in five may experience headache or body aches, joint pain, vomiting, diarrhea or a rash. While serious illness and death are rare, fatigue and weakness from the virus can last weeks or even months.

Those most at risk are people 60 and older or with certain medical conditions, including cancer, diabetes, hypertension and kidney disease.

The Department of Health said people should take measures to prevent mosquito bites and reduce the bugs’ breeding grounds. Specifically, the agency said to do the following:

• Properly use an EPA-approved insect repellent when around mosquitoes.
• Use screens on windows and doors, and repair holes in them to keep bugs out.
• Try to avoid spending time outside at dawn and dusk, when the bugs are most active.
• Cover yourself with a hat, long sleeves and pants when going into mosquito-heavy areas.
• Use permethrin on clothing to kill or repel mosquitoes.
• Empty anything with standing water that mosquitoes use to breed, such as clogged gutters and puddles in tarps. If you can’t empty the spaces, cover them or change the water at least twice a week.

For more information on West Nile, go to doh.wa.gov/you-and-your-family/illness-and-disease-z/west-nile-virus.