The Sin Nombre Virus is a type of hantavirus that primarily affects humans and is transmitted through contact with infected rodents, particularly the deer mouse. It was first identified in the United States in the late 1990s and is known to cause a severe respiratory disease called hantavirus pulmonary syndrome (HPS). Symptoms of HPS can include fever, muscle aches, and difficulty breathing, which can progress rapidly. The virus is typically spread through inhalation of aerosolized particles from rodent droppings, urine, or saliva. Preventive measures include avoiding contact with rodents and maintaining clean environments to reduce rodent populations.