Hantavirus Transmission — Primary, Secondary, and Person-to-Person Routes
Hantaviruses are rodent-borne. Humans are accidental, dead-end hosts for almost every serotype. Transmission is overwhelmingly via inhalation of aerosolised rodent excreta in enclosed spaces. Andes virus is the sole exception — it has documented person-to-person transmission, primarily between close household contacts.
Primary route: rodent-to-human aerosol
Infected rodents shed virus in urine, faeces, and saliva. When dried excreta is disturbed — by sweeping, vacuuming, or vehicle movement in a barn or cabin — virus-laden particles aerosolise and can be inhaled. Risk is highest in poorly-ventilated, rodent-infested structures: cabins, outbuildings, grain stores, agricultural sheds, abandoned vehicles, military barracks, and rodent-occupied apartments.
Secondary routes
- Direct rodent bite — rare, but documented for Seoul virus from pet rats in the US and UK.
- Mucous-membrane contact — eye-rubbing after handling rodent material is a plausible inoculation route.
- Contaminated food — possible but rare; not a mainstream transmission mode.
- Laboratory exposure — historical lab outbreaks during early hantavirus research; modern BSL-3 containment makes this rare.
Andes virus person-to-person transmission
Andes virus (ANDV) is the only orthohantavirus with documented P2P transmission. Cluster evidence comes from:
- El Bolsón, Argentina (1996) — Wells et al. described 20 cases linked through close-contact transmission, including healthcare workers and household contacts.
- Coyhaique, Chile (2018–2019) — sequenced clusters showing inter-person transmission between non-household close contacts.
- MV Hondius cluster (2026) — actively monitored. Onboard spread is suspected given the long voyage and shared crew quarters; HORIZON ontology models this explicitly under the "transmitted_to" relationship between the index couple.
P2P transmission appears to require close, prolonged contact rather than fleeting exposure. Universal precautions, droplet isolation for known/suspected ANDV cases, and respirator use during aerosol-generating procedures are recommended by Argentine and Chilean health authorities during active outbreaks.
What does NOT transmit hantavirus
- Mosquitoes, ticks, or any arthropod vector — hantaviruses are not arboviruses despite the "haemorrhagic fever" naming.
- Casual contact with HPS/HFRS patients (except for ANDV close contacts) — this is not an airborne respiratory virus in the SARS-CoV-2 sense.
- Food prepared in non-rodent-contaminated kitchens.
- Blood transfusion (no documented cases).
- Sexual transmission (no documented cases).
Reservoir species — primary rodent hosts
| Serotype | Reservoir | Region |
|---|---|---|
| ANDV | Oligoryzomys longicaudatus (long-tailed pygmy rice rat) | Argentina, Chile, southern Patagonia, Tierra del Fuego |
| SNV | Peromyscus maniculatus (deer mouse) | United States Four Corners region, Canada, Mexico |
| PUUV | Myodes glareolus (bank vole) | Scandinavia, Baltic states, central Europe, European Russia |
| HTNV | Apodemus agrarius (striped field mouse) | China, Korean peninsula, far-eastern Russia |
| SEOV | Rattus norvegicus (brown rat), Rattus rattus (black rat) | Worldwide via global Rattus distribution |
| DOBV | Apodemus flavicollis (yellow-necked mouse) | Balkans, central Europe, European Russia |
| BAYV | Oryzomys palustris (marsh rice rat) | Southeastern United States |
| LANV | Calomys laucha (small vesper mouse) | Paraguay, Bolivia, Argentina |
See prevention for evidence-based measures to reduce exposure risk in endemic regions.