What Is Hantavirus?
Last updated: May 9, 2026 · Sources: WHO, CDC, ECDC
Overview
Hantaviruses are a family of RNA viruses (Hantaviridae) carried by rodents and transmitted to humans primarily through inhalation of aerosolized excreta (urine, feces, saliva). They cause two main clinical syndromes: Hantavirus Pulmonary Syndrome (HPS), predominant in the Americas, and Hemorrhagic Fever with Renal Syndrome (HFRS), found mainly in Europe and Asia.
The first hantavirus was isolated in 1978 in South Korea from the striped field mouse near the Hantan River — giving the family its name. Since then, over 50 strains have been described worldwide.
Andes Virus — The Most Dangerous Strain
The Andes virus (ANDV), first documented in Argentina and Chile in 1995, is unique among all known hantaviruses: it is the only strain capable of spreading from person to person, though this remains rare and typically requires close, sustained contact (e.g., within households or between intimate partners).
Its reservoir is the long-tailed rice rat (Oligoryzomys longicaudatus), abundant in the Andean-Patagonian forests of Argentina and Chile. Case fatality rates for ANDV-associated HPS range from 30–40% — significantly higher than most other strains.
Transmission
- →Inhalation (primary route): Breathing in aerosols from rodent urine, feces, or nesting material. Risk is highest in poorly ventilated enclosed spaces (cabins, barns, outbuildings).
- →Direct contact: Touching rodents or their excreta and then touching the nose or mouth.
- →Bite: Rare — being bitten by an infected rodent.
- →Person-to-person (Andes virus only): Documented in Argentina and Chile. Requires close, prolonged contact — typically household or intimate partner exposure. NOT spread by casual contact or aerosol in open air.
Main Strains Worldwide
| Strain | Disease / CFR | Risk |
|---|---|---|
| Andes virus (ANDV) | HPS · up to 40% mortality · person-to-person transmission | Very High |
| Sin Nombre (SNV) | HPS · ~36% mortality | High |
| Hantaan (HTNV) | HFRS · ~5–15% mortality | High |
| Seoul (SEOV) | HFRS · mild-moderate | Low–Moderate |
| Puumala (PUUV) | Nephropathia epidemica · <1% mortality | Moderate |
| Dobrava (DOBV) | HFRS · variable | Moderate |