Hantavirus Symptom Checker
& Exposure Risk Tool

The earliest signs of hantavirus pulmonary syndrome (HPS) include high fever (101–104°F), severe muscle aches concentrated in the thighs, hips, back, and shoulders, and profound fatigue. About half of patients also experience nausea, vomiting, or diarrhea. These symptoms appear 1 to 8 weeks after exposure. There are no early respiratory symptoms — shortness of breath signals dangerous progression to the cardiopulmonary phase.

Early HPS and flu are nearly indistinguishable by symptoms alone. The key differentiators are:

(1) Environmental context — HPS requires a recent, significant rodent exposure event. Flu does not.

(2) Absence of upper respiratory symptoms — Hantavirus typically does not cause a runny nose, sneezing, or sore throat in early stages. Flu often does.

(3) Respiratory progression — HPS rapidly advances to severe shortness of breath and fluid in the lungs. This is rare in healthy adults with seasonal flu.

Yes — if the droppings are from an infected deer mouse and you stir them up dry (sweeping, vacuuming, or disturbing nesting materials). The risk is dramatically reduced by wetting the droppings first with a bleach solution, wearing an N95 respirator, and ensuring the space is well-ventilated for at least 30 minutes before cleaning. Touching droppings while wearing gloves without stirring dust is very low risk.

The incubation period is 1 to 8 weeks, with most cases becoming symptomatic within 2 to 4 weeks of exposure. This wide range makes pinpointing the exact exposure event difficult. If you develop flu-like symptoms within this window after a known rodent exposure, seek medical evaluation.

No — North American hantavirus strains (particularly Sin Nombre virus) are not known to spread person to person. You can only contract HPS through direct contact with infected rodents, their urine, feces, or saliva, or by inhaling aerosolized particles from those materials. There is no evidence of transmission through coughing, touching an infected person, or shared surfaces.

The primary carrier is the deer mouse (Peromyscus maniculatus), responsible for most US HPS cases (Sin Nombre virus). Other carriers include the white-footed mouse, rice rat, and cotton rat (different hantavirus strains). Importantly, common house mice (Mus musculus) are NOT known carriers of hantavirus in North America. Deer mice are common in rural, semi-rural, and woodland areas across the western US.

There is currently no FDA-approved vaccine or specific antiviral treatment for HPS in the United States. Treatment is supportive: intensive monitoring, supplemental oxygen, IV fluids, and in severe cases, mechanical ventilation and ECMO (extracorporeal membrane oxygenation). The key to survival is early hospitalization — the cardiopulmonary phase can deteriorate within hours.

Hantavirus is extremely rare. The CDC records approximately 20–50 confirmed HPS cases annually in the United States. Since the disease was first characterized in 1993, there have been fewer than 1,000 total confirmed US cases (CDC). The mortality rate is high (~38%), but the statistical probability of infection from casual or brief encounters with rodents is exceptionally low — particularly for people in urban settings.

Yes, a properly fitted N95 or P100 respirator provides meaningful protection against inhaling hantavirus particles during rodent cleanup. Standard surgical masks, cloth masks, and basic dust masks do not provide adequate filtration for aerosolized hantavirus. The CDC explicitly recommends wearing an N95 or better when cleaning any space with confirmed rodent activity.

If you had significant exposure to a rodent-contaminated enclosed space (especially without an N95 respirator):

(1) Monitor for symptoms for up to 8 weeks — particularly fever, muscle aches, and fatigue.

(2) Seek care immediately if you develop shortness of breath, chest pain, or rapidly worsening symptoms.

(3) Tell your provider about the exposure. Many emergency departments may not immediately consider HPS without this history.

Do not wait to see if shortness of breath resolves on its own — this is a medical emergency in the context of rodent exposure.