Hantavirus: Complete Guide to Symptoms, Diagnosis, Therapy and Prevention (2026)

1. What Is Hantavirus and Why It Matters in 2026

Hantaviruses are a group of single-stranded RNA viruses from the Hantaviridae family that circulate in rodents and other small mammals across nearly every continent. They do not cause disease in their animal hosts, but when humans inhale aerosolised dust contaminated with rodent urine, droppings or saliva, the virus can trigger two distinct and serious syndromes: hemorrhagic fever with renal syndrome (HFRS) in Europe and Asia, and hantavirus pulmonary syndrome (HPS) in the Americas.

The topic gained renewed global attention in May 2026 when the WHO and the ECDC confirmed a cluster of Andes virus infections among passengers and crew on the Dutch expedition vessel MV Hondius, which had departed from Ushuaia, Argentina, on April 1, 2026. As of May 8, 2026, eight cases and three deaths were reported, including one German national. The outbreak is the largest documented Andes virus event linked to a single travel exposure and has reopened the conversation about hantavirus preparedness in Europe.

For people in Germany the picture is different but not less important. According to the Robert Koch-Institut (RKI), Puumala virus is responsible for the overwhelming majority of human hantavirus cases in Germany, with regional hotspots in the Swabian Alb, the Bavarian Forest, the Aschaffenburg-Wuerzburg corridor, the Odenwald and parts of Hesse and the Muensterland. In the first quarter of 2026 alone, Baden-Wuerttemberg registered 38 laboratory-confirmed Puumala HFRS cases, all of whom recovered.

This guide explains, in plain language, what hantavirus is, how it is transmitted, what the symptoms look like at each stage, how doctors diagnose and treat it, and what you can do to lower your personal risk. It is written for general readers in Germany and Europe and is updated as of May 2026.

2. Hantavirus Types: Old World vs. New World

"Hantavirus" is not a single virus. It is an umbrella term for more than 40 known viral species, several of which are pathogenic to humans. Researchers usually divide them into two broad groups based on their geographic origin and the syndrome they cause.

Old World hantaviruses (Europe and Asia)

These viruses typically cause HFRS, an illness that primarily affects the kidneys and the vascular system. The most relevant species are:

• Puumala virus (PUUV) - by far the most common cause of hantavirus infection in Germany and large parts of Northern, Western and Central Europe. Its natural host is the bank vole (Myodes glareolus). Puumala causes a milder form of HFRS, sometimes called nephropathia epidemica, with a case fatality rate of well below 1 percent.
• Dobrava-Belgrade virus (DOBV) - found mainly in the Balkans and in eastern parts of Germany up to the Weser river. Its main reservoir is the striped field mouse (Apodemus agrarius). The Kurkino genotype circulating in Germany is generally milder than the Balkan strains.
• Hantaan virus (HTNV) - the prototypical and most severe Old World hantavirus, found across East Asia. Mortality of classic Hantaan-HFRS can reach 5 to 15 percent without modern intensive care.
• Seoul virus (SEOV) - distributed worldwide via Norway rats and brown rats. Causes a moderate HFRS course and has been documented in pet rat colonies in several European countries.

New World hantaviruses (the Americas)

These viruses cause HPS, a syndrome dominated by acute lung injury and cardiac complications.

• Sin Nombre virus (SNV) - the dominant cause of HPS in North America, hosted by the deer mouse (Peromyscus maniculatus). Case fatality is around 30 to 40 percent.
• Andes virus (ANDV) - the only hantavirus for which sustained person-to-person transmission has been documented. Found in Argentina and Chile. Andes virus is responsible for the 2026 MV Hondius outbreak.

The distinction between Old World and New World viruses is important because it determines which organ systems are mainly affected, how transmission can occur and what the prognosis looks like.

3. How Hantavirus Spreads

Hantavirus is a textbook example of a zoonosis - a disease that crosses from animals to humans. The reservoir is always a small mammal, most often a wild rodent. Infected animals shed virus particles in their urine, droppings and saliva. Once these excretions dry out, viral particles can attach to dust and remain infectious for several days under the right conditions.

For people in Germany and Europe the typical transmission scenarios look like this:

• Inhalation of contaminated dust - the most important route. Sweeping out a dusty barn, shed, attic or holiday cabin in spring after a rodent winter can release a fine bioaerosol that is inhaled into the lungs.
• Direct contact with surfaces or food contaminated by rodent excretions, followed by hand-to-face contact or accidental ingestion.
• Contact between contaminated material and broken skin - relevant for foresters, hunters and agricultural workers.
• Rodent bites - rare but documented, particularly in laboratory settings or with pet rats.

One reassuring point: for the European hantaviruses Puumala and Dobrava-Belgrade, person-to-person transmission has not been documented. Caregivers and household contacts of HFRS patients do not need to isolate. The Andes virus in South America is the exception to this rule and the reason public health authorities are watching the Hondius cluster so closely.

Risk also follows the rodent cycle. After mast years - autumns with abundant beech and oak seeds - bank vole populations explode the following spring, and human Puumala cases tend to spike a few months later. The pattern is well established and forms the basis of the seasonal risk forecasts published by the RKI and the Bavarian Health and Food Safety Authority (LGL).

4. Hantavirus in Germany: Risk Areas and Current Numbers

Hantavirus has been notifiable in Germany since 2001. Looking at the long-term RKI data, case counts swing dramatically from year to year, driven by rodent ecology. Outbreak years can see more than 2,000 notifications nationally, while quiet years stay below 300.

The geographical distribution is highly uneven. The high-risk regions are:

• Baden-Wuerttemberg - especially the Swabian Alb, Upper Swabia and the Odenwald, where extensive beech forests sustain large bank vole populations.
• Bavaria - particularly the area around Aschaffenburg, Wuerzburg, Lower Franconia and parts of the Bavarian Forest. Bavaria saw a marked rise in 2025.
• Hesse - the central uplands and the Spessart.
• North Rhine-Westphalia - the Muensterland and the Sauerland.
• Lower Saxony and Thuringia - patchy distribution, with localised hotspots.

Eastern federal states such as Mecklenburg-Vorpommern, Brandenburg and Saxony-Anhalt see a different pattern dominated by the Dobrava-Belgrade Kurkino genotype, carried by the striped field mouse.

The 2026 picture so far is moderate. The RKI's early-2026 reports show 38 confirmed Puumala HFRS cases in Baden-Wuerttemberg by mid-April, with no fatalities. That is below the levels seen in high mast years like 2007, 2010, 2012, 2017 and 2019, when several thousand cases were registered nationally. Climate variability, beech mast cycles and changing land use are expected to keep hantavirus a recurring topic for the foreseeable future.

5. Symptoms: HFRS and HPS Compared

Hantavirus symptoms unfold in phases. The incubation period - the time between exposure and the first signs of illness - is usually 2 to 4 weeks but can range from 1 to 8 weeks. This long window is one reason the diagnosis is often delayed.

HFRS (the European form, including Puumala)

Most patients describe an illness that begins like influenza and then transitions into a kidney problem. A classic course has five overlapping phases:

1. Febrile phase (3 to 7 days) - sudden high fever (often above 39 degrees Celsius), severe headache (especially behind the eyes), back pain, muscle aches, abdominal pain, blurred vision and a flushed face. Many patients are initially diagnosed with flu, COVID-19 or a kidney infection.
2. Hypotensive phase (hours to 2 days) - blood pressure drops, sometimes to shock levels. Capillaries become "leaky" and fluid moves out of the blood vessels.
3. Oliguric phase (3 to 7 days) - urine output decreases sharply, sometimes to almost nothing. Kidney values worsen and patients may need temporary dialysis.
4. Polyuric phase (days to weeks) - kidney function returns and patients pass very large amounts of urine. Dehydration and electrolyte shifts are the main risks here.
5. Convalescence (weeks to months) - gradual recovery. Most patients regain normal kidney function, but fatigue and back pain can persist for months.

For Puumala specifically, the course is usually milder. Many patients have only flu-like symptoms with a brief kidney involvement and recover at home. Case fatality is well below 1 percent. Dobrava-Belgrade Kurkino sits in a similar mild range, while Hantaan virus in Asia can be considerably more severe.

HPS (the American form)

HPS follows a very different and usually more dramatic course:

1. Prodromal phase (3 to 7 days) - fever, fatigue, muscle aches (especially thighs, hips, back and shoulders), headache, dizziness, chills, nausea and abdominal pain. Cough and shortness of breath may already begin.
2. Cardiopulmonary phase - rapid onset of severe shortness of breath and a feeling of tightness in the chest. The lungs fill with fluid, oxygen levels fall and many patients need mechanical ventilation. Cardiac function can deteriorate and shock can develop within hours.
3. Diuretic and convalescent phase - if the patient survives the cardiopulmonary phase, recovery can be relatively quick, but full lung function may take weeks to months to return.

Mortality of HPS, including Sin Nombre and Andes virus, has historically been around 35 to 40 percent. Early hospitalisation with intensive care and, where available, extracorporeal membrane oxygenation (ECMO) has improved survival significantly.

If you are wondering how to tell hantavirus apart from influenza or COVID-19 in the early phase, the honest answer is: clinically, you often cannot. That is why exposure history (rodents, dusty work, travel to endemic regions) and laboratory testing matter so much.

6. Diagnosis: Antibody Tests, PCR and Rapid Tests

The diagnosis of hantavirus disease relies on a combination of clinical suspicion, exposure history and laboratory testing. There is no single perfect test for every stage of the disease.

Serology (antibody testing)

Serology is the diagnostic mainstay in Germany and across Europe. Standard laboratory methods are:

• IgM ELISA - detects fresh infection. IgM antibodies are usually present at symptom onset and remain detectable for several months, sometimes up to two years.
• IgG ELISA - indicates either ongoing or past infection. A rising IgG titre between two samples taken 1 to 2 weeks apart confirms acute infection.
• Immunoblot / line assay - used to confirm ELISA results and to differentiate between Puumala, Dobrava-Belgrade and other species.
• Indirect immunofluorescence assay (IFA) - a classic reference method, still used in specialised laboratories.

A positive IgM result in a patient with compatible symptoms (fever, headache, kidney involvement) is normally enough to confirm the clinical diagnosis. Simultaneous IgM and IgG positivity, or a clear IgG titre rise, is even more reliable.

Molecular testing (RT-PCR)

RT-PCR can detect viral RNA in blood during the very first days of illness, but viraemia is brief and the window is narrow. A negative PCR therefore does not rule out hantavirus disease. PCR is mainly used in early or atypical cases and for genotyping outbreak strains, as currently being done for the Andes virus on the MV Hondius.

Rapid tests

Lateral flow rapid tests for Hantavirus IgG and IgM antibodies are commercially available and are used both in clinical settings and in field surveillance. They provide a qualitative result within 10 to 20 minutes from a small amount of serum, plasma or whole blood. Rapid tests are particularly useful when fast triage is needed - for example in regional emergency departments during outbreak years, or to screen exposed groups such as forestry workers.

Rapid hantavirus antibody tests do not replace laboratory ELISA or PCR confirmation but they help to flag suspicious cases quickly. As with all serological assays, the test result must be interpreted in the clinical context. A negative test in the first 24 to 48 hours of symptoms can be a false negative because antibodies have not yet built up. In such cases, repeat testing 72 hours later or a confirmatory PCR is advised.

If you suspect hantavirus exposure or want to learn more about the rapid tests we offer for respiratory and viral diseases, our respiratory rapid test collection is a good starting point. We are actively expanding our viral diagnostics portfolio, so it is worth checking back as new options become available.

Additional laboratory findings

Doctors usually order a broader workup that supports the diagnosis indirectly:

• Elevated serum creatinine and urea (kidney involvement)
• Thrombocytopenia (low platelet count)
• Elevated C-reactive protein
• Proteinuria and microscopic hematuria in urine analysis
• Elevated LDH and liver enzymes in some cases

7. Therapy: What Doctors Can Do

As of May 2026, there is no licensed antiviral drug that cures hantavirus infection. Treatment is supportive and aims to keep the patient alive and stable while the immune system clears the virus. Despite the lack of a specific therapy, outcomes are generally good for the Puumala form most commonly seen in Germany.

Standard supportive measures include:

• Fluid management - careful intravenous fluid balance to maintain blood pressure during the hypotensive phase without overloading the leaky capillaries.
• Pain and fever control - paracetamol is generally preferred. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or diclofenac should be avoided because they can worsen kidney function.
• Renal replacement therapy - temporary dialysis is occasionally needed during the oliguric phase. Long-term dialysis is rare for Puumala.
• Intensive care - HPS patients typically require ICU admission, supplemental oxygen and often mechanical ventilation. ECMO is reserved for the most severe cases and has been shown to improve survival when initiated early.
• Cardiovascular support - vasoactive drugs in shock, careful monitoring of cardiac function.

Hospitalisation is recommended for moderate and severe cases. Patients with mild Puumala disease can sometimes be managed as outpatients, with close monitoring of kidney values and blood pressure.

Several experimental therapies are being studied, including monoclonal antibodies against Andes virus and broad-spectrum antivirals such as favipiravir. None of these has reached routine clinical use.

8. Prevention: How to Protect Yourself

Because there is no vaccine and no specific drug, prevention is the most powerful tool against hantavirus. The RKI, together with the Charite and several other research institutions, has published a detailed information sheet on how to avoid hantavirus infection. The core recommendations are easy to translate into everyday behaviour.

Inside the home

• Keep food in sealed metal or glass containers. Do not leave pet food out overnight.
• Empty waste bins regularly and store rubbish in closed containers, ideally outside the main living area.
• Seal openings in walls, roofs, foundations and around pipes that are larger than 5 millimetres - that is enough for a young mouse to enter.
• Use mechanical mouse traps in basements, attics and storage rooms. Avoid sticky traps from a welfare perspective.

When cleaning rodent-contaminated spaces

This is the highest-risk activity and the situation in which most German Puumala infections originate. Follow these steps:

1. Ventilate the room for at least 30 minutes before entering.
2. Wear disposable gloves and an FFP2 or FFP3 respirator. Surgical masks are not sufficient.
3. Spray dead mice, nests, droppings and urine-soaked material with a disinfectant solution before touching them. This prevents dust formation.
4. Place all material in a sealed plastic bag and dispose of it with normal household waste.
5. Wipe surfaces with a damp cloth and disinfectant. Avoid dry sweeping or vacuuming, which aerosolises virus particles.
6. Wash hands thoroughly with soap and water afterwards.

Outdoors

• Wear gloves when stacking firewood, working in the garden or handling compost.
• Keep distance from visible rodent burrows when hiking, especially in known endemic areas.
• Do not handle dead rodents with bare hands.

Travel to high-risk regions

If you travel to South America, especially Patagonia and the Andes region, where the Andes virus circulates, the recommendations are stricter. Avoid sleeping in cabins, sheds and rural buildings that show signs of rodent activity. Choose lodging that is regularly cleaned. The Hondius outbreak has reinforced the importance of these basic precautions.

9. Risk Groups: Who Should Be Especially Careful

While anyone can be infected, certain groups have a clearly elevated risk based on their work or living environment:

• Forestry and agricultural workers - regular contact with rodent habitats and dusty environments.
• Construction and demolition workers - especially during renovation of older buildings.
• Hunters and trappers - direct handling of small mammals.
• Soldiers and people doing field exercises - dusty bivouacs in endemic regions.
• Laboratory personnel working with rodents.
• People with rural holiday homes in endemic regions, who clean cabins after the winter.
• Pet rat owners - documented Seoul virus infections in Europe.

For these groups, occupational health guidelines recommend respiratory protection, gloves and clear procedures for handling potentially contaminated material.

10. Vaccine Research: Where We Stand

Despite decades of research, there is currently no hantavirus vaccine licensed for use in Europe or North America. Several reasons explain this slow progress: the disease is geographically and seasonally clustered, the commercial market is limited, and historically there has been more public health investment in influenza and coronaviruses than in hantaviruses.

Some inactivated whole-virus vaccines against Hantaan and Seoul virus are in use in South Korea and China, where Hantaan-HFRS is a major occupational disease, but these products are not approved in the European Union and provide little cross-protection against Puumala or Andes virus.

In May 2026, in the immediate aftermath of the Hondius outbreak, several groups including the US Army Medical Research Institute of Infectious Diseases (USAMRIID) confirmed that pre-clinical candidates against Andes virus exist. Realistic estimates suggest at least 3 to 4 years before human Phase 1 trials, and 5 or more years before any product could be licensed - assuming sustained funding.

Until then, the only effective prevention is behavioural: rodent control, dust-avoidance during cleaning, respiratory protection and, where relevant, careful travel planning.

11. The 2026 MV Hondius Outbreak in Context

The Hondius cluster matters for two reasons. First, it is the largest cruise-ship hantavirus outbreak ever documented. Second, it involves Andes virus, the only hantavirus that can transmit between people. As of May 8, 2026, the WHO reported eight cases with three deaths, including one German national. Passengers and crew from multiple countries were affected, and contact tracing covers travellers across the European Union, the United States and several South American countries.

The European Centre for Disease Prevention and Control (ECDC) assessed the risk to the general EU/EEA population from this outbreak as very low. The reasoning is straightforward: Andes virus does not circulate in European rodent populations, and the secondary transmission risk requires close prolonged contact. The Robert Koch-Institut and the Friedrich-Loeffler-Institut have confirmed that the situation for native European hantaviruses such as Puumala and Dobrava-Belgrade remains unchanged.

What the outbreak has changed is awareness. Travel medicine clinics across Europe report a clear increase in hantavirus-related consultations, and several European public health agencies have updated their travel advice for the Patagonia and Andes regions. The episode is also prompting renewed discussion about hantavirus surveillance, antiviral pipelines and outbreak response capacity in non-endemic regions.

12. Frequently Asked Questions

How long after exposure do symptoms appear?

Most patients fall ill 2 to 4 weeks after exposure. The full range is 1 to 8 weeks. If you developed flu-like symptoms a few weeks after cleaning a dusty barn or cabin, mention this to your doctor.

Can I catch hantavirus from another person in Germany?

For Puumala and Dobrava-Belgrade, no documented case of human-to-human transmission exists. The Andes virus in South America is the exception, but it does not circulate in Europe.

Is hantavirus more dangerous than COVID-19 or influenza?

The total number of cases is much lower than for COVID-19 or seasonal flu, but the case fatality rate is higher, especially for HPS. With early hospitalisation, outcomes for European HFRS are generally good and most patients recover fully.

What should I do if I find a dead mouse at home?

Ventilate the room for 30 minutes. Wear disposable gloves and an FFP2 mask. Spray the animal with disinfectant, place it in a sealed plastic bag and dispose of it with household waste. Wash hands thoroughly.

Are there rapid tests for hantavirus?

Yes, lateral flow IgG and IgM antibody tests exist and are used in clinical and field settings. They support but do not replace laboratory confirmation by ELISA or PCR.

Should I worry if I live in Berlin or Hamburg?

The hantavirus risk in major urban centres in Northern Germany is low compared with the Swabian Alb or Lower Franconia. Risk is closely tied to forest and rodent ecology. Travelling to or holidaying in an endemic region is a more relevant exposure factor than your everyday city life.

Does hantavirus leave long-term damage?

Most Puumala patients recover full kidney function within months. Persistent fatigue, mild proteinuria or back pain have been reported in a minority of cases. Severe HPS survivors can experience reduced lung function for months.

13. Conclusion

Hantavirus is not a new disease. It has been part of the European infection landscape for decades, with predictable peaks tied to beech mast and bank vole cycles. The 2026 MV Hondius outbreak has put the topic back into the headlines and reminded both the public and policymakers that emerging viral threats are rarely far away.

For people living in Germany, the practical takeaways are clear. Know the regional risk - the Swabian Alb, the Bavarian Forest, the Aschaffenburg area and the Muensterland deserve special attention. Take rodent infestations seriously and follow the RKI cleaning rules. If you develop a high fever, severe headache and back pain after a possible exposure, mention the exposure to your doctor. Rapid serological tests and laboratory confirmation can shorten the path to the right diagnosis.

Until a hantavirus vaccine becomes available, prevention and early recognition are the most powerful tools we have. Stay informed, protect yourself when cleaning dusty environments, and consider serological testing whenever symptoms and exposure history fit the pattern. Our respiratory rapid test collection brings together the diagnostics we offer for viral respiratory infections, and we are continuously expanding the range as new tests reach the market.

For related reading, our guides on comparing flu, RSV and COVID symptoms and Long COVID research may help you put hantavirus into a broader respiratory-viral context.

If you want to take a fast first step at home or in your practice, you can buy the Hantavirus rapid test directly from us. It complements - but does not replace - laboratory confirmation by ELISA or PCR.

Last updated: May 2026. This article is intended for general information and does not replace medical advice. If you suspect a hantavirus infection, contact your doctor or a hospital emergency department immediately.