Hantavirus is a family of viruses spread primarily by rodents that can cause severe, potentially fatal respiratory or kidney disease in humans. In May 2026, a strain known as the Andes virus caused an outbreak aboard the cruise ship MV Hondius, putting hantavirus in global headlines for the first time in years.
Hantaviruses are RNA viruses in the family Hantaviridae. They are classified as zoonotic viruses, meaning they are transmitted from animals to humans. Different species of hantavirus are found worldwide, each typically associated with a specific rodent host.
Unlike many other viral diseases, hantavirus cannot spread from person to person in most cases — with one notable exception: the Andes virus, found in South America, has been documented to transmit between humans through close contact, making the 2026 cruise ship outbreak particularly concerning to health authorities.
2026 Outbreak Update: The Andes hantavirus strain has been confirmed aboard the MV Hondius cruise ship. As of May 7, 2026: 8 cases, 3 deaths, 6 countries affected. See the full outbreak timeline →
There are dozens of known hantavirus species. The most clinically important fall into two main categories based on the disease they cause:
| Type | Disease Caused | Region | Fatality Rate |
|---|---|---|---|
| Andes virus | Hantavirus Pulmonary Syndrome (HPS) | Argentina, Chile | 25–40% |
| Sin Nombre virus | Hantavirus Pulmonary Syndrome (HPS) | North America | 30–40% |
| Hantaan virus | Haemorrhagic Fever with Renal Syndrome (HFRS) | Asia, Europe | 5–15% |
| Seoul virus | HFRS (milder) | Worldwide (via rats) | <1% |
| Puumala virus | Nephropathia Epidemica (mild HFRS) | Europe | <1% |
| Dobrava virus | HFRS (severe) | Balkans, Europe | 1–12% |
The primary route of hantavirus infection is through inhalation of aerosolised particles from infected rodent urine, faeces, or saliva. Transmission can also occur through:
Activities that increase risk include cleaning rodent-infested areas, camping or hiking in endemic regions, and living or working in locations with high rodent populations.
Cleaning barns, sheds or cabins · Hiking/camping in endemic areas · Agricultural work · Disturbing rodent nests · Working in warehouses or grain stores
Urban living · Routine outdoor activities away from rodent habitat · Visiting areas without confirmed hantavirus rodent reservoirs · Using well-sealed buildings
Hantavirus is found on every continent except Antarctica and Australia. The specific strains and their rodent hosts vary by region:
Argentina has reported a significant increase in hantavirus infections in 2025–2026, with the health ministry recording approximately 101 cases since June 2025 — nearly double the prior year's figure. Climate change may be expanding rodent ranges and food sources, contributing to increased transmission.
Hantavirus infection is diagnosed by blood tests, including enzyme-linked immunosorbent assay (ELISA) for antibodies and reverse transcriptase polymerase chain reaction (RT-PCR) for viral RNA. The 2026 MV Hondius outbreak was confirmed by RT-PCR at South Africa's National Institute for Communicable Diseases (NICD) and Geneva University Hospitals.
There is currently no approved antiviral treatment for hantavirus and no licensed vaccine available outside of limited use in some Asian countries for HFRS strains. Treatment is primarily supportive:
Ribavirin, an antiviral drug, has been studied but evidence for its effectiveness in HPS is limited. Early hospitalisation significantly improves survival odds.
The most effective way to prevent hantavirus infection is to avoid exposure to rodents and their droppings. Key precautions include:
Follow the MV Hondius hantavirus outbreak in real time on our interactive map.