Hantavirus is a group of viruses found worldwide that spread to humans primarily through contact with infected rodents. People become infected by breathing in tiny particles from rodent droppings, urine, or saliva — often while cleaning sheds, cabins, or other enclosed spaces where mice or rats have been living. In the Americas, the deer mouse is the most common carrier of the Sin Nombre virus, the strain responsible for most U.S. cases.
The disease typically begins with flu-like symptoms: fever, muscle aches, fatigue, and sometimes nausea or abdominal pain. Within days, it can progress to serious breathing problems as fluid fills the lungs — a condition known as hantavirus pulmonary syndrome. In parts of Europe and Asia, a different form called hemorrhagic fever with renal syndrome can cause kidney damage and internal bleeding. Both forms can be lifethreatening, with fatality rates ranging from about 1% to as high as 40% depending on the virus strain.
There is currently no vaccine or specific antiviral treatment for hantavirus. Care focuses on early recognition and intensive supportive treatment, including oxygen and mechanical ventilation when needed. Early medical attention significantly improves survival.
Prevention is the best defense. Seal gaps in homes to keep rodents out. Avoid sweeping or vacuuming rodent droppings, which can send particles airborne — instead, wet them down with a bleach solution before cleanup. When camping or hiking, store food securely and avoid sleeping near rodent burrows. If you develop sudden fever and shortness of breath after possible rodent exposure, seek medical care immediately.
