Transmission
How do you get hantavirus?
Hantavirus reaches humans almost entirely through one route: breathing in dust contaminated with rodent urine, feces or saliva. There is no mosquito or tick that carries it, and — with one exception — no person-to-person spread.
The primary route — aerosol from rodent excreta
When dried rodent droppings, urine deposits or nest material are disturbed (sweeping, vacuuming, walking through a dusty cabin), they release tiny particles into the air. Inhaling those particles delivers virus to lung tissue, where it crosses into the small blood vessels and seeds infection.
About 90% of US cases trace to household or occupational exposure of this kind.
Other documented routes
- Rodent bites or scratches — rare but reported.
- Ingestion of food or water contaminated by rodent waste.
- Direct contact with broken skin or mucous membranes — also rare.
The Andes-virus exception
Andes virus, found in southern Argentina and Chile, is the only hantavirus with confirmed person-to-person transmission. The clearest evidence is the 2018–2019 outbreak in Epuyén, Patagonia: 34 confirmed cases and 11 deaths from a single rodent introduction amplified at social events; secondary transmission peaked on the first febrile day. The 2026 cruise-ship cluster fits the same pattern.
What does not spread it
- Mosquitoes, ticks, fleas — no arthropod vector.
- Casual contact with an HPS patient (except Andes virus).
- Cooked food.
- Domestic dogs and cats — they don't develop the disease and don't transmit it. They can, however, drag infected rodents into the home.
Higher-risk situations
- Opening a closed cabin, shed or barn at the start of the season.
- Cleaning rodent-infested storage spaces.
- Agricultural work — handling hay, grain, barn debris.
- Hiking and camping in rodent-occupied shelters.
- Pet-rat keeping with non-screened breeders (Seoul virus).
- Travel to Patagonia during reported Andes-virus activity.
Frequently asked questions
Is hantavirus contagious between people?
Almost never. Andes virus in South America is the only documented exception.
Is hantavirus airborne?
Yes in the sense that contaminated dust gets aerosolized and inhaled. No in the sense that it doesn't sustain long-distance respiratory spread the way measles does.
How do you get hantavirus from mice?
By inhaling dried-out urine and feces particles when dust is disturbed. The mice themselves stay infected for life and shed virus in their excreta without symptoms.
Can you get hantavirus from rats?
Yes — Seoul virus is carried by brown and black rats globally and has caused human cases, including pet-rat clusters in the US and UK.
Can you get hantavirus from dogs or cats?
No. Pets don't carry the disease. They can bring infected rodents indoors, which is the actual exposure route.
See Prevention for the CDC's cleanup protocol that stops aerosols at the source, and Syndromes for what infection looks like clinically.