State health officials on Friday confirmed two cases of West Nile disease in Washington residents -- the state's first cases in humans since 2010.
A Pierce County woman in her 70s came down with West Nile disease after traveling outside of the state. A Yakima man in his 30s also contracted the disease, but he had not traveled outside of Washington, according to the Washington State Department of Health.
While these are the first state cases of West Nile in humans, state health officials have confirmed the disease in mosquitoes and animals in Washington.
Last month, a horse in Yakima County was euthanized after contracting the disease. And health officials detected West Nile disease in five mosquito pools, which are groups of mosquitoes taken from a location and tested, in Yakima and Franklin counties.
"West Nile virus is hitting many parts of the nation hard this season, so it's not surprising we'd have cases among people in our state," Washington Secretary of Health Mary Selecky said in a news release.
Clark County has not reported any cases of West Nile in mosquito pools, animals or people this year. However, crews are finding mosquitoes that can carry the disease, said John Jacobson, Clark County Mosquito Control District crew supervisor.
Crews regularly trap adult flying mosquitoes to monitor population numbers and test for the West Nile virus, he said. In addition, crews will continue spraying catch basins and retention ponds -- mosquito breeding grounds -- until at least Oct. 1.
The public can also help curb the mosquito population growth by removing sources of standing water, such as buckets and tires, and changing the water in bird baths and animal troughs twice a week, Jacobson said.
People can protect themselves from mosquito bites by avoiding being outside at dawn and dusk when mosquitoes are most active, wearing long-sleeved shirts and pants, and using proven mosquito repellent, he said.
West Nile virus is almost always transmitted to people who are bitten by an infected mosquito. Mosquitoes get the disease from feeding on infected birds.
As of Tuesday, 48 states have reported West Nile virus infections in people, birds or mosquitoes, according to the Centers for Disease Control and Prevention.
The CDC has recorded 1,993 human cases of West Nile virus -- the most reported through the first week of September since the virus was first detected in the U.S. in 1999. Eighty-seven people have died from the disease this year.