Hantavirus is carried by rodents especially deer mice. The virus is found in rodents’ urine, droppings and saliva. Humans can become infected with the virus when they come in contact with contaminated dust from mice nests or droppings. It appears that symptoms can develop between one and five weeks after exposure to fresh urine, droppings or saliva from the infected rodents. A total of 728 cases have been reported in the U.S as of January 2017.