Hantavirus – Closer Than You Think, Deadlier Than You’d Expect

When people think of animal-borne infectious diseases, many think of rabies, bird flu, or COVID. But there is another virus that is no less dangerous and is hiding closer to us than we might think: the “hantavirus,” a virus spread by wild rodents that can take human lives at an alarming rate. This article will introduce you to this virus from every angle.

What Is Hantavirus?

Hantavirus (scientific name Orthohantavirus) is a group of viruses spread mainly by rodents, and it can cause severe illness or death.

The name “hanta” comes from the Hantan River in South Korea, which is where this group of viruses was first discovered.

At present, there are more than 28 species of hantavirus that cause disease in humans. They can be divided into two major groups according to region and the type of illness they cause: the group that causes lung disease, and the group that causes kidney disease.

The Two Main Forms of Disease

1. Hantavirus Pulmonary Syndrome (HPS)

This disease is found on the American continents and is caused by the “New World” group of hantaviruses. It is a very dangerous disease because its initial symptoms resemble those of a common cold, making it difficult to diagnose in the early stage, yet it can progress to the point where the patient has difficulty breathing.

In the United States, the key virus that causes this disease is the Sin Nombre virus, which is spread by deer mice in the genus Peromyscus. What makes HPS frightening is its fatality rate: among patients with severe respiratory symptoms, the fatality rate is estimated at approximately 38%.

2. Hemorrhagic Fever with Renal Syndrome (HFRS)

This disease is found mainly in Europe and Asia and is caused by the “Old World” group of hantaviruses. Its prominent symptoms focus on the kidneys rather than the lungs, including headache, abdominal pain, fever, nausea, bleeding, and kidney failure. This disease has far more cases worldwide than HPS, with an estimated 100,000 HFRS cases per year, while HPS has fewer than 50 cases per year, but its fatality rate is lower.

One interesting point is that the Seoul virus, a hantavirus that causes HFRS, is found worldwide, including in the United States.

How Is It Transmitted?

This is an important part that everyone should know. Transmission of hantavirus to humans occurs through contact with the urine, droppings, or saliva of infected rodents, and can also occur through rodent bites, although this is less common.

But the most common route is when the urine, droppings, or nesting materials of infected rodents are disturbed and become airborne; the virus rises into the air, and a person can become infected by breathing in the contaminated air. In addition, the virus can spread when the saliva, urine, or droppings of an infected animal enter through a wound on the skin, or through the eyes, nose, or mouth.

Activities that increase risk include cleaning enclosed or poorly ventilated spaces, farming, forestry work, and sleeping in rodent-infested dwellings. The risk is often higher when opening or cleaning rural buildings that have been closed up over the winter, which is the period when rodents move in to live.

However, most hantaviruses are generally not transmitted from person to person. There is only one exception: the Andes virus, which is the only hantavirus known to spread from person to person. This spread is usually limited to people in close contact with the patient. The Andes virus is found in the South American region, and the rodents that carry this virus have not yet been found in the United States.

What Are the Symptoms?

The incubation period is fairly long, with symptoms usually beginning between 1 and 8 weeks after exposure, depending on the type of virus.

Early symptoms often trick people into thinking it is another illness, because initial symptoms such as fever, headache, muscle aches, nausea, and fatigue can easily be confused with influenza or other viral illnesses. In addition, about half of HPS patients experience headache, dizziness, chills, and gastrointestinal symptoms such as nausea, vomiting, diarrhea, and abdominal pain.

Severe symptoms follow later. The late-stage symptoms of HPS appear about 4–10 days after the initial phase and include coughing, difficulty breathing, and chest tightness. In severe cases, it can progress to respiratory failure and shock.

Diagnosis and Treatment

Diagnosis is difficult in the early stage because the symptoms are non-specific, so doctors rely on both a history of rodent exposure together with laboratory testing. Testing for hantavirus antibodies in the blood is the primary diagnostic tool, and the CDC uses the ELISA method to detect IgM antibodies in order to diagnose acute infection.

What must be clearly understood is that at present there is no FDA-approved hantavirus vaccine in the United States, and there is no specific antiviral medication for this infection. Treatment is therefore supportive: patients are given rest, adequate hydration, and symptomatic care. In cases of difficulty breathing, a ventilator may be required, such as intubation, while HFRS patients with abnormal kidney function may need dialysis.

Although there is no direct cure, starting treatment as early as possible is very important because it helps increase the chance of survival. Therefore, anyone who has a fever, difficulty breathing, and has recently been in contact with rodents or materials contaminated by rodents should see a doctor promptly and immediately report their history of rodent exposure.

How to Prevent It

The heart of prevention is rodent control, which is the primary strategy for preventing the disease. Wild rodents living near communities should be controlled and kept from entering homes. The key principle is to avoid contact with the urine, droppings, saliva, and nesting materials of rodents.

When cleaning an area with rodents, what you should not do is sweep or vacuum the dry dust, because that causes the virus to become airborne.

The recommendations are:

• Spray the area with disinfectant or a bleach-water solution to wet it first, leave it for a while, and then wipe it up.
• Wear gloves and a protective mask while cleaning.
• Seal off the routes rodents use to enter the home, store food securely, and eliminate places where rodents might nest.

Latest Situation: The 2026 Cruise Ship Cluster

What brought hantavirus back into attention was a recent event. On 2 May 2026, a cluster of cruise ship passengers ill with severe respiratory disease was reported to the World Health Organization. The ship was carrying a total of 147 passengers and crew. As of 4 May 2026, 7 cases had been found (2 confirmed hantavirus infections and 5 suspected), including 3 deaths. Subsequently, the Andes virus was confirmed as the cause of this outbreak, which is consistent with the fact that it is the only type that can spread from person to person.

Comparison Table: HPS vs. HFRS

Topic	HPS (Pulmonary Symptoms)	HFRS (Hemorrhagic Fever + Renal Failure)
Region found	The Americas	Europe and Asia
Main organ affected	Lungs	Kidneys
Cases per year	Fewer than 50	Approximately 100,000
Fatality rate	High (~38% in severe cases)	Lower (<1%–15%)
Virus types found	Sin Nombre, Andes	Seoul, Hantaan

Conclusion

Hantavirus is an uncommon but life-threatening disease, especially the pulmonary syndrome (HPS), which has a high fatality rate. The key point to remember is that this virus is spread mainly by rodents, not from person to person (with the exception of the Andes virus). There is still no specific vaccine or cure, so the best prevention is rodent control and avoiding contact with materials contaminated by rodents. And if you develop cold-like symptoms after contact with rodents, especially if they are followed by difficulty breathing, do not delay in seeing a doctor.

Note: This article was compiled from information by the CDC, WHO, and public health agencies. It is intended for general knowledge, not as medical advice. If you have any health concerns, please consult a doctor directly.