Rodents may be chronically infected with hantavirus and shed the virus for months. There are no documented cases of hantavirus being transmitted from infected patients to health care workers. The first symptoms of HPS associated with Sin Nombre virus in the U.S. usually occur 2-3 weeks after exposure and are flulike in nature. Within 3-4 days, rapid onset of severe respiratory failure may follow. This is characterized by high mortality despite mechanical ventilation and intense care.
Rodents are the primary reservoir hosts of all recognized hantaviruses.
Each hantavirus appears to have a preferential rodent host, but other small mammals can be infected as well, The primary reservoir for Sin Nombre virus appears to be the deer mouse, Peromyscuc maniculatus. The deer mouse is highly adaptable and is found in different habitats throughout the U.S. including human residences in rural and semirural areas, but generally not in urban centers. Hantaviruses do not cause apparent illness in their reservoir hosts. Known infections are associated with domestic, occupational, or leisure activities that bring humans into contact with infected rodents, usually in a rural setting. Any individual with a suspected case should see their physician.