2026 Hantavirus Live Tracker

A rodent-borne virus with two faces

Hantaviruses are a group of viruses carried by rodents, mice, rats and voles, that occasionally jump to humans. People get infected by breathing in tiny particles from contaminated rodent urine, droppings or saliva, usually when disturbing dust in an enclosed space. A bite or scratch from an infected rodent can also transmit the virus, though that is uncommon.

The disease looks different depending on where you are. In the Americas, hantaviruses attack the lungs, causing hantavirus pulmonary syndrome (HPS), a condition that floods the lungs with fluid and can kill up to half of those infected. In Europe and Asia, the target shifts to the kidneys and blood vessels, producing hemorrhagic fever with renal syndrome (HFRS), which is serious but less often fatal.

The virus is not new. The first recognised outbreak struck the Four Corners region of the American Southwest in 1993, though the virus family has likely circulated in rodent populations for centuries. WHO estimates between 10,000 and 100,000 human infections occur globally each year, with the heaviest burden in China and northern Europe.

What makes Andes virus different

Most hantaviruses are a dead end in humans, the infection passes from rodent to person and stops there. Andes virus, found in southern Argentina and Chile, is the sole exception. It is the only known hantavirus that can spread from one person to another, though this remains rare and requires close, sustained contact: sharing meals, kissing, handling contaminated bedding, or breathing the same confined air during the early days of illness.

That distinction is what turned a single infection aboard the MV Hondius into an international event. Had the virus been Sin Nombre (the North American strain) or Puumala (the common European strain), the first patient would have been the only case. Because it was Andes virus, and because a cruise ship forces 150 people into shared dining rooms, corridors and lounges, the conditions for human-to-human transmission were present in a way they almost never are on land.

A virus out of place

Andes hantavirus belongs to the forests and grasslands of southern Argentina and Chile. Its natural host is the long-tailed pygmy rice rat, a rodent that has never been found outside South America. Yet in April 2026 the virus appeared aboard a cruise ship in the middle of the Atlantic, thousands of kilometres from any known reservoir.

Argentine investigators now believe a Dutch couple contracted the virus during a birdwatching excursion to a landfill near Ushuaia before boarding the MV Hondius on 1 April. The couple had spent months crossing between Argentina, Chile and Uruguay, passing through Neuquén and Misiones, both WHO-designated endemic zones. The Malbrán Institute is trapping and testing rodents along their route to confirm the source.

What makes this cluster scientifically notable is what happened next. Andes virus is the only hantavirus known to spread between people, and even that is rare. But inside the confined quarters of a 196-berth expedition ship, close contact turned one infection into eight cases across four continents, echoing a 2019 "super-spreader" event in Epuyén, Argentina, where a single introduction led to 34 infections.

Hantavirus at a glance

• Family of rodent-borne viruses in the order Bunyavirales
• Americas: causes HPS (hantavirus pulmonary syndrome), up to 50% fatal
• Europe/Asia: causes HFRS (hemorrhagic fever with renal syndrome), <1–15% fatal
• Incubation: 1–8 weeks, typically 2–4 weeks
• Person-to-person spread documented only for Andes virus, and only through close prolonged contact
• No licensed antiviral or vaccine exists anywhere
• Treatment is supportive: ICU monitoring, oxygen, fluid balance
• WHO estimates 10,000–100,000 infections globally per year, mostly in Asia

How HPS unfolds

The first passenger on the MV Hondius fell ill on 6 April with what looked like a stomach bug, fever, headache, abdominal pain, diarrhea. Five days later he was dead. That rapid escalation is the hallmark of hantavirus pulmonary syndrome.

Days 1–4 (prodromal):

• Abrupt high fever, often above 38.5 °C
• Deep muscle pain concentrated in the thighs, hips and lower back
• Fatigue, headache, dizziness, chills
• Nausea, vomiting, abdominal cramps, diarrhea

Days 4–10 (cardiopulmonary):

• Dry cough progressing to severe shortness of breath
• Fluid flooding the lungs (pulmonary edema)
• Falling blood pressure and rapid heart rate
• Acute respiratory distress syndrome (ARDS) and shock

About 38% of patients who reach the respiratory phase die from it, according to CDC data. The window between "bad flu" and ICU is often less than 48 hours, which is why early recognition matters more than any drug.

How to protect yourself

Rodent avoidance (primary defense):

• Seal gaps wider than 6 mm in walls, foundations and utility conduits
• Store food in sealed containers; clean spills the same day
• Remove brush, woodpiles and clutter near buildings

Safe cleanup of droppings:

• Ventilate the room for 30 minutes before entering
• Spray droppings with disinfectant or 1:9 bleach, wait 5 minutes
• Wipe with paper towels, double-bag all waste
• Wear N95 mask and gloves throughout, never dry-sweep or vacuum

For MV Hondius returnees and contacts:

• Self-monitor for 42 days (the maximum Andes incubation window)
• If fever + muscle aches develop, go to hospital, do not wait
• Tell the clinician about your travel and ship exposure immediately
• Avoid sharing utensils, towels or sleeping spaces until cleared