HPS was first reported in the United States in the spring of 1993. About 38 percent of the people died as a result of the infection. Twenty-two HPS cases have been reported in Washington. Three cases have been reported in Lewis County and two each in Lincoln, Stevens, Adams, Franklin, Grant, Klickitat, King, Snohomish, and Yakima counties. San Juan county has had one case.
Symptoms usually begin one to three weeks after exposure to infected deer mice.
HPS is characterized by fever, chills and muscle aches, followed by the abrupt onset of respiratory distress and shortness of breath. The muscle aches are severe, involving the thighs, hips, back and sometimes the shoulder. Other symptoms include nausea, vomiting, and abdominal pain. The deer mouse can carry and shed the virus without showing any signs of being sick. The deer mouse is about six inches long to the tip of its tail.