What Is Andes Hantavirus? The Pathogen Behind the Hondius Outbreak
Andes virus is the only hantavirus with documented person-to-person spread. Here's what's known about its biology, transmission, and clinical course.
A South American hantavirus with one unique trait
Andes virus (ANDV) is a member of the Orthohantavirus genus carried in nature by the long-tailed pygmy rice rat (Oligoryzomys longicaudatus) across Argentina and Chile (CDC overview).
What makes ANDV unusual among hantaviruses is person-to-person transmission. Most hantaviruses spread only through aerosolised rodent excreta. ANDV has documented human-to-human spread in clusters dating back to a 1996 outbreak in El Bolsón, Argentina, and a 2018-19 cluster in Epuyén (NPR explainer, 5 May 2026; Science News, May 2026).
Clinical course
ANDV causes Hantavirus Pulmonary Syndrome (HPS) — also called Hantavirus Cardiopulmonary Syndrome:
- Incubation: typically 2–4 weeks (range up to 6 weeks)
- Prodrome: 3–5 days of fever, severe muscle aches, headache, gastrointestinal symptoms
- Cardiopulmonary phase: rapid-onset pulmonary oedema, shock, often within hours
- Case-fatality ratio: historically 30–40% in confirmed HPS cases (ECDC RRA, 6 May 2026)
There is no specific antiviral and no licensed vaccine. Treatment is supportive: aggressive ICU care, mechanical ventilation, and in severe cases extracorporeal membrane oxygenation (ECMO).
Why an Atlantic cruise ship is unprecedented
Hantavirus clusters are normally tied to rural exposure to rodents. A cluster on a vessel mid-Atlantic, far from ANDV's natural rodent reservoir, points strongly to person-to-person spread as the propagation mechanism — which is why WHO, ECDC and Africa CDC moved so quickly (Ars Technica, May 2026).
Primary references: ECDC, US CDC, WHO, peer-reviewed literature on Andes virus.
