What health authorities want you to know about hantavirus pulmonary syndrome, how it spreads, and why respiratory protection matters.
Hantavirus is a family of viruses primarily carried by rodents. When humans come into contact with infected rodent droppings, urine, or saliva — or breathe in air particles contaminated with these materials — they can contract a serious respiratory illness known as Hantavirus Pulmonary Syndrome (HPS).
HPS is rare but extremely dangerous. According to the CDC, roughly 36% of confirmed U.S. cases are fatal. There is no specific antiviral treatment approved for hantavirus — medical care focuses on supportive treatment including oxygen therapy and mechanical ventilation in severe cases.
Most hantaviruses found in the United States, including the Sin Nombre virus responsible for the majority of U.S. cases, spread only from rodents to humans. The Andes virus, found primarily in South America (Argentina and Chile), is the sole known exception to this rule.
The Andes strain has been documented in clusters where transmission occurred between people in close contact — particularly between household members or caregivers. This characteristic is what makes outbreaks involving the Andes strain so alarming to public health officials and why they demand a higher level of respiratory protection than typical rodent-exposure scenarios.
| Characteristic | Sin Nombre Virus (U.S.) | Andes Virus (South America) |
|---|---|---|
| Primary carrier | Deer mouse | Long-tailed rice rat |
| Geographic range | U.S. Southwest, rural areas | Argentina, Chile; global via travel |
| Person-to-person spread | No | Yes (documented) |
| Case fatality rate | ~36% | ~35–40% |
| Airborne transmission | From rodent particles only | From rodent particles + close human contact |
| Confined space risk | Moderate | Higher (person-to-person possible) |
The CDC identifies three primary routes of infection:
Hantavirus symptoms typically develop one to eight weeks after exposure. The illness progresses in two distinct phases:
Roughly half of HPS patients enter this severe phase, which can develop rapidly within 24–48 hours. It is characterized by:
There is no vaccine and no specific cure. Early hospitalization and intensive care are the only interventions that improve survival odds.
Rodent populations thrive in enclosed environments — storage areas, basements, attics, and outbuildings. When humans disturb these spaces, they risk aerosolizing contaminated particles. Crucially, the virus can remain viable in dry droppings for several days, meaning a space does not need to have active rodent presence to pose a risk.
In confined spaces like ships, underground facilities, or rural cabins with limited ventilation, contaminated air particles have less opportunity to disperse. This is why public health authorities have flagged enclosed vessel environments as elevated-risk scenarios in connection with hantavirus cases involving the Andes strain.
Standard surgical masks and cloth face coverings do not provide adequate protection against hantavirus exposure. The CDC recommends the following for activities involving potential rodent-contaminated environments:
NIOSH-approved N95 respirators filter at least 95% of airborne particles and form a tight seal around the face. They are the minimum recommended protection level for cleaning spaces with potential rodent contamination.
P100 filters remove 99.97% of airborne particles — the highest filtration level available in standard respirator equipment. Full-face models also protect the eyes and mucous membranes. These are recommended for high-risk or extended exposure scenarios, professional remediation work, or any environment with confirmed rodent infestation.
Health authorities recommend N95 or P100 respirators for any activity involving potential rodent-contaminated environments. These are the top-rated options, currently discounted.
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Last reviewed: May 2026. This page provides educational information only. Consult a healthcare professional for medical advice.