Current Situation in the United States (2026)
As of May 2026, hantavirus (HPS) remains an endemic disease in the western United States. CDC surveillance tracks confirmed HPS cases reported by state health departments. Cases typically peak in spring and summer when people come into contact with rodent-infested spaces after winter.
The general public risk from hantavirus in the United States remains low. HPS is not contagious between people — infection requires direct contact with infected rodent excreta. Most cases occur in rural settings among individuals who work outdoors or disturb rodent habitats in poorly ventilated enclosed spaces.
Hantavirus Cases by State
Case data by state is reported to the CDC. As of May 2026, historically most confirmed HPS cases have occurred in western states including New Mexico, Colorado, Arizona, California, and Montana. Since surveillance began in 1993, cases have been reported across most states wherever deer mice are present.
For current, official state-level data, visit CDC's HPS tracking page ↗
Symptoms and When to Seek Emergency Care
HPS progresses in two phases. The early phase resembles influenza and may last 3–5 days. The cardiopulmonary phase that follows is life-threatening and requires immediate emergency care.
Early Phase (Days 1–5)
- Fever (38–40 °C / 100–104 °F)
- Fatigue and severe muscle aches
- Headache
- Nausea or vomiting
- Dizziness
Cardiopulmonary Phase (Days 5–10) — EMERGENCY
- Dry cough
- Shortness of breath
- Rapid respiratory failure
- Pulmonary oedema (fluid in lungs)
- Cardiogenic shock in severe cases
When to seek emergency care
If you develop shortness of breath, rapid breathing, or feel like your lungs are filling with fluid within 1–2 weeks of possible rodent exposure, call 911 or go to an emergency room immediately. Tell healthcare providers about possible rodent contact. Early ICU admission significantly improves survival in HPS (CDC, PAHO).
Deer Mouse and Sin Nombre Virus — Primary Reservoir in the US
The deer mouse (Peromyscus maniculatus) is the primary reservoir for Sin Nombre virus, the hantavirus responsible for most HPS cases in the United States. Deer mice are found throughout North America, particularly in rural and semi-rural areas, forests, fields, and agricultural settings.
Infected deer mice shed the virus in their urine, droppings, and saliva throughout their lives without becoming ill. The virus can survive for hours to days in the environment, especially in cool, moist, and shaded conditions. People are exposed when they inhale dust contaminated with rodent excreta, most commonly in enclosed spaces like cabins, sheds, barns, or vehicles that have been closed over winter.
For more detail, see our guide on deer mouse and hantavirus.
How People Get Infected
- Inhalation: The most common route. Stirring up dust in areas with rodent droppings, urine, or nesting materials releases virus particles into the air.
- Direct contact: Touching rodent droppings or urine and then touching the mouth, nose, or eyes.
- Rodent bites: Rare, but possible if handling wild rodents.
- Person-to-person: Does not occur with Sin Nombre virus in the US. (Only Andes virus in South America has documented person-to-person transmission.)
How to Clean Mouse Droppings Safely
Never sweep or vacuum dry mouse droppings — this can aerosolize virus particles. Follow CDC guidance:
- Ventilate the area for at least 30 minutes before entering (open windows and doors).
- Wear rubber, latex, or vinyl gloves.
- Spray droppings and nesting materials with a disinfectant or bleach solution (1.5 cups bleach per gallon of water). Let soak for 5 minutes.
- Wipe up with paper towels and place in a sealed plastic bag. Double-bag and dispose in a covered trash can.
- Disinfect gloves before removing, then wash hands thoroughly with soap and water.
For complete guidance, see our rodent dropping cleanup guide and the official CDC cleanup instructions ↗.
Prevention Checklist (CDC-Based)
Seal holes and gaps (larger than ~6 mm) where rodents could enter homes or outbuildings.
Store food (including pet food) in sealed, rodent-proof containers.
Keep trash bins tightly covered and empty them regularly.
Keep wood piles, brush, and debris away from building walls.
Avoid sweeping or vacuuming mouse droppings — wet with disinfectant first.
Wear rubber gloves when cleaning areas with rodent activity.
Ventilate closed spaces (cabins, sheds, barns) for 30 minutes before entering.
Avoid camping or sleeping near areas with signs of rodent activity.
Use airtight containers or elevated platforms for food storage when camping.
For more prevention strategies, see our comprehensive hantavirus prevention guide and the outdoor risk reduction guide.
Official Sources
Frequently Asked Questions — Hantavirus in the United States
What type of hantavirus is found in the United States?
The primary hantavirus in the United States is Sin Nombre virus, which causes Hantavirus Pulmonary Syndrome (HPS). The deer mouse (Peromyscus maniculatus) is the main reservoir. Other rodent-borne hantaviruses occasionally detected in the US include Black Creek Canal virus and Bayou virus, but Sin Nombre accounts for the vast majority of confirmed HPS cases (CDC).
How many hantavirus cases occur in the US each year?
CDC surveillance data shows approximately 20–40 confirmed HPS cases per year in the United States, with significant year-to-year variation depending on rodent population cycles and weather conditions. Since surveillance began in 1993, over 800 cases have been confirmed with a case fatality rate of approximately 36%. For current case counts, consult CDC.gov/hantavirus.
Which US states have the most hantavirus cases?
Historically, western states account for the majority of US HPS cases. New Mexico, Colorado, Arizona, California, and Montana have reported the highest cumulative case totals. Cases have been reported in most states, however, and risk exists wherever deer mice are present. For state-level data, visit CDC's HPS tracking page.
How do you get hantavirus in the United States?
In the US, hantavirus infection occurs almost exclusively through inhalation of aerosolized particles from deer mouse droppings, urine, or saliva. This most commonly happens when disturbing rodent nests in closed, poorly ventilated spaces such as cabins, barns, or sheds. Unlike Andes virus in South America, Sin Nombre virus does not spread person-to-person.
What are the symptoms of hantavirus in the US?
Early symptoms of HPS resemble the flu: fever, fatigue, muscle aches, headache, and sometimes nausea or vomiting. After 3–5 days, coughing and shortness of breath develop as the lungs fill with fluid. This cardiopulmonary phase is life-threatening and requires immediate emergency care. Anyone with these symptoms after possible rodent exposure should call 911 or go to an emergency room immediately.
Is there a hantavirus vaccine in the United States?
No. There is currently no licensed vaccine for hantavirus in the United States. Treatment is supportive — fluids, oxygen, and mechanical ventilation in severe cases. Prevention through rodent control and avoiding exposure to rodent droppings is the most effective approach (CDC).
How do I safely clean mouse droppings to avoid hantavirus?
CDC recommends: (1) Ventilate the area for at least 30 minutes before entering; (2) Wear rubber or plastic gloves; (3) Do NOT sweep or vacuum dry droppings — this can aerosolize the virus; (4) Spray droppings with a bleach solution (1.5 cups per gallon of water) and let soak for 5 minutes; (5) Wipe up with paper towels and dispose in sealed trash bags. See the full CDC guidance at CDC.gov/hantavirus.
Medical disclaimer: This page is for educational purposes only and does not replace professional medical advice. If you suspect hantavirus infection after rodent exposure, seek emergency care immediately. For official US guidance, consult CDC.gov/hantavirus or your state health department.