The virus causes fever, headache, back pain, chills and nausea. In rare cases, the virus can cause renal failure and hemorrhagic bleeding. Patients who develop these rare serious symptoms face a mortality rate of approximately one to two percent. Investigators then looked at rat breeders who supplied the rats to the first patient in Wisconsin. They found six who also tested positive for the Seoul virus. The virus is not passed person to person, but from infected rats to people via the rat’s droppings, saliva or urine or after exposure to dust from nests or bedding. Even if patients can recover from the ill in many cases in one to eight weeks, there is no cure for the virus.