Officials for Washington State University say the fungus can cause an illness called valley fever. The fungus is normally found in semiarid parts of the Southwest.
Valley fever occurs when the soil-dwelling fungus becomes airborne, releasing spores that get lodged in the lungs of humans and certain animals, especially dogs.
The Centers for Disease Control estimates it kills 160 people a year.
Three unrelated cases were diagnosed in Eastern Washington in 2010-11. The patients lived within a 60-mile radius of Benton, Franklin, and Walla Walla counties.