Bob Lunsford, director of Freshwater Fisheries for the Department of Natural Resources, said most of the affected trout appear to be rainbows, although some brown trout have shown symptoms.
The disease is an infection caused by a microscopic parasite and is named for the characteristic swimming behavior that results as the parasite multiplies in the head and spinal cartilage of the infected fish, according to the Whirling Disease Foundation.
Source: The Washington Times