🐀 Hantavirus
Hantavirus is a family of viruses spread primarily by rodents. In the Americas, the primary disease it causes is Hantavirus Pulmonary Syndrome (HPS), a severe respiratory illness that CDC reports is fatal in 38% of people who develop respiratory symptoms. Unlike most respiratory viruses, most hantavirus strains are not spread from person to person — infection is acquired by inhaling dust contaminated with infected rodent droppings, urine, or saliva. (The Andes virus, found in South America, is the only known exception.)
Key facts
- HPS is fatal in 38% of people who develop respiratory symptoms; 35% across all 890 confirmed U.S. cases 1993–2023 (CDC)
- No FDA-approved antiviral treatment; care is supportive
- Sin Nombre virus is the primary U.S. strain, carried by deer mice
- Spring cleaning, camping, and agricultural work are common exposure scenarios
Most-asked questions
- What are hantavirus symptoms?
- How is hantavirus transmitted?
- How do I prevent hantavirus exposure?
- What is the treatment for hantavirus?
- Where do hantavirus outbreaks occur?
These questions are answered in depth on HantavirusQuestions.com.
What is hantavirus?
Hantaviruses are a genus of single-stranded RNA viruses in the family Hantaviridae. Each strain is associated with a specific rodent reservoir host. In the Americas, the Sin Nombre virus — carried by deer mice (Peromyscus maniculatus) — causes most cases of Hantavirus Pulmonary Syndrome (HPS). In Europe and Asia, Puumala and Hantaan viruses cause Hemorrhagic Fever with Renal Syndrome (HFRS), which primarily affects the kidneys rather than the lungs. (CDC: About Hantavirus)
How hantavirus is transmitted
Humans are infected by breathing in air contaminated with virus particles from infected rodent droppings, urine, or saliva — particularly when dust is disturbed during cleaning activities in enclosed spaces such as cabins, sheds, and storage areas. How long the virus stays infectious on surfaces has not been measured for Sin Nombre virus, the U.S. strain; laboratory work on related hantaviruses found Puumala virus infectious in soiled rodent bedding for 12–15 days at room temperature and inactivated within 24 hours at 37°C (Kallio et al., J Gen Virol 2006), which is why CDC's cleanup rules target the mechanism — ventilate, wet everything down, never sweep — rather than a waiting time.
Person-to-person transmission does not occur in the United States with Sin Nombre virus. The Andes virus strain (found in South America) is the only known hantavirus with documented person-to-person transmission. That exception produced the first shipboard hantavirus cluster on record in 2026: 13 Andes virus cases and 3 deaths among the 147 people aboard the cruise ship MV Hondius, with contact tracing in 33 countries and territories and no secondary case off the ship. WHO declared it over on 2 July 2026; no U.S. case was linked to it. (CDC: About Andes Virus; WHO Disease Outbreak News, 2 July 2026)
Who is at risk?
Anyone who comes in contact with infected rodents or their droppings is at risk. High-risk activities include cleaning rodent-infested spaces, camping in areas with rodent populations, agricultural work, and entering buildings that have been closed for extended periods. CDC has recorded 890 laboratory-confirmed cases in the United States from 1993 through 2023, 94% of them west of the Mississippi; New Mexico, Colorado and Arizona lead the cumulative count, and CDC's provisional weekly tables show 38 cases in 2025. Roughly a third of confirmed cases have been fatal. (CDC: Reported Cases of Hantavirus Disease)
Prevention
No hantavirus vaccine is licensed in the United States or Europe (inactivated vaccines against other hantaviruses exist in Korea and China). Prevention relies entirely on reducing rodent exposure:
- Seal entry points — close gaps larger than ¼ inch in buildings and vehicles.
- Eliminate food sources — store food and pet food in rodent-proof containers.
- Clean safely — wear gloves, spray droppings and nests with a disinfectant or a bleach solution (CDC's recipe: 1 part bleach to 9 parts water) until wet, wait five minutes, and wipe up; never sweep or vacuum. For heavy infestations CDC specifies a HEPA-filtered half-mask or powered respirator.
- Ventilate before entry — open windows and doors for 30 minutes before entering a closed building suspected of rodent infestation.
- Traps and rodenticides — reduce local rodent populations around the home and outbuildings.
(CDC: Hantavirus Prevention; CDC: How to Clean Up After Rodents)
How Hantavirus compares to other viruses
A case fatality rate on its own is hard to read — 38% sounds catastrophic, 0.1% sounds trivial, and neither tells you how the virus sits against anything else. This section places Hantavirus against the other viruses in the network's 15-virus dataset, which is maintained here on the hub rather than on any single-virus site.
- Case Fatality Rate 38% 1 higher, 8 lower, of 10 reporting this
4 of the five metrics are not published for Hantavirus — annual exposure / cases, severe outcome rate, hospitalization rate, annual deaths. Those cells are left empty rather than estimated. A blank is not a low number: it means the measurement does not exist, and reading it as zero would make the least-studied diseases look like the safest ones.
In-depth answers at HantavirusQuestions.com
Complete pages on symptoms (HPS vs. HFRS), transmission, prevention protocols, treatment, outbreak history, FAQ, and a buying guide for rodent-proofing and cleanup supplies. Updated with current research.
This page provides a summary of hantavirus. For comprehensive information, visit HantavirusQuestions.com. Summarized from CDC and WHO guidance. Last reviewed: .