What is Hantavirus? Everything you need to know about this rare but serious virus

Hantavirus is not a condition most people spend much time thinking about. It rarely appears in mainstream health coverage, and compared with infections such as la grippe, norovirus, or COVID, public awareness remains low.

So when it suddenly makes headlines, the same questions come up - what is it, how serious is it, and should we be worried?

In the case of hantavirus, the honest answer is that it deserves respect - but not panic.

It can cause serious, even life-threatening illness. But it is also rare, does not spread easily between people, and for most people in the UK, the risk remains extremely low.

What is hantavirus?

Hantavirus is the name given to a group of viruses carried by rodents.

Different strains are found in different parts of the world, and each tends to be associated with particular species of mice, rats, or voles.

These animals usually show no obvious signs of illness, but they can carry and shed the virus in their pee (urine), poo (droppings), and saliva.

Human infection typically happens through environmental exposure rather than direct contact.

In simple terms, the virus can become airborne in tiny particles of dust contaminated by rodent waste, and infection can occur when that dust is breathed in.

The current coverage follows reports of several passengers becoming seriously unwell aboard the expedition vessel MV Hondius after a South American itinerary.

Public health investigations are ongoing, and while laboratory-confirmed cases have been reported, officials believe exposure may have taken place during activities on land rather than on the ship itself.

That distinction matters, because hantavirus behaves very differently from respiratory viruses that spread in crowded indoor spaces. It is not something currently spreading through communities, schools, offices or public transport.

The current incident appears to be linked to a very specific exposure event rather than broader human transmission.

In almost all cases, no.

That is one of the most reassuring things about hantavirus. The vast majority of infections occur through direct exposure to contaminated environments rather than through contact with another infected person.

There is one notable exception, a strain known as Andes virus, found mainly in parts of South America, where limited person-to-person transmission has been documented.

Outside of that, hantavirus is generally considered a dead-end infection in humans.

If someone becomes infected, the people around them are not usually considered at risk simply through normal day-to-day contact.

Yes, although cases are uncommon.

The UK Health Security Agency (UKHSA) recognises hantavirus infection as a rare but established disease in Britain.¹

British rodent populations, including rats and voles, can carry strains capable of infecting humans, although confirmed cases remain infrequent.

Where infections do occur, they are more often seen in people whose work or hobbies involve close contact with rural buildings, livestock areas, feed stores, or rodent habitats.

That might include:

• Farmers.

• Grounds staff.

• Pest controllers.

• Forestry workers.

• Stable owners.

• Builders and renovators.

• People restoring caravans, boats or outbuildings.

Even in these groups, infection remains rare.

People often initially feel as though they are coming down with a viral infection such as the rhume or flu.

That alone would not immediately suggest hantavirus. What makes the infection concerning is that in some cases symptoms can worsen quickly over the following days.

Depending on the strain involved, more serious complications may affect either the lungs or the kidneys.

Other strains may cause:

• Severe back pain.

• Douleur abdominale.

• Peeing less than normal.

• Kidney inflammation.

For clinicians, the combination of symptoms plus an exposure history is often what raises suspicion.

A recent history of clearing rodent-infested spaces, handling feed stores, working in barns, or travelling in rural parts of affected countries can be an important clue.

Hantavirus can be serious. The most severe form, known as Hantavirus pulmonary syndrome (HPS), can progress rapidly and may require intensive care support. Another severe syndrome associated with hantavirus is haemorrhagic fever with renal syndrome (HFRS), which is mainly seen in Europe and Asia.²

Data from the Centers for Disease Control and Prevention (CDC) suggests that around 38% of people who develop severe pulmonary disease may not survive, even with modern treatment.³

That sounds alarming, and it should be taken seriously. But it is equally important to remember that these severe cases are rare, and the overall number of infections remains very small.

There is currently no widely used antiviral treatment specifically for hantavirus.

Management is supportive and may include:

• Oxygen therapy.

• Intravenous fluids.

• Intensive care monitoring.

• Kidney support in severe cases.

As with many infections, early recognition can make a significant difference.

For most people, no.

There is currently no evidence of wider public health risk in the UK linked to the latest outbreak, and no reason for people to change travel plans, avoid public places, or worry about day-to-day contact with others.

The main risk remains environmental exposure in settings where rodents may be present.

For most people, hantavirus will remain something they read about rather than experience.

But for those who work regularly in rural environments, old buildings, barns, stables, or storage spaces, it’s a useful reminder that sometimes the simplest precautions still matter.