Orthohantavirus facts for kids

Quick facts for kids Orthohantavirus
Transmission electron micrograph of Sin Nombre virus
Virus classification
Unrecognized taxon (fix):	Orthohantavirus
Species
#Classification
Synonyms
Hantavirus

Orthohantavirus is a group of tiny living things called viruses. These viruses are often called hantaviruses. They can make people sick. Hantaviruses usually live in rodents like mice and rats. Each hantavirus often lives in one type of rodent. The rodents usually do not get sick from the virus. But in humans, hantaviruses can cause two main illnesses. These are called hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS).

HFRS is mostly found in Africa, Asia, and Europe. It affects the kidneys. HPS is usually found in North and South America. It causes serious breathing problems. Hantaviruses spread mainly through tiny particles in the air. These particles come from rodent droppings, urine, or saliva. People can also get sick from contaminated food, bites, or scratches from infected rodents. Weather and environment can also affect how these viruses spread.

Understanding Hantavirus Illnesses

Hantaviruses cause two main types of sickness in people. These are HFRS and HPS. The chance of getting very sick or dying from HFRS is usually less than 1% to 15%. For HPS, this risk is higher, from 30% to 60%.

Hemorrhagic Fever with Renal Syndrome (HFRS)

HFRS is caused by hantaviruses found in Africa, Asia, and Europe. Symptoms usually appear 12 to 16 days after someone is exposed to the virus. This illness affects the kidneys. The kidneys can swell, and there might be too much protein or blood in the urine. Other symptoms include headache, back pain, upset stomach, and sometimes small spots on the skin. Recovery can take a few months. Some milder forms of HFRS are called nephropathia epidemica. Once a person recovers, they likely have protection from getting the same hantavirus again.

Hantavirus Pulmonary Syndrome (HPS)

HPS is mainly caused by hantaviruses in North and South America. Symptoms usually start 1 to 8 weeks after exposure. Early symptoms are like the flu, with fever, headache, and muscle pain. People might also feel short of breath. The illness can quickly lead to serious breathing problems. Fluid can build up in the lungs, making it very hard to breathe. This can be very dangerous. Recovery typically takes 3 to 6 months.

How Hantaviruses Spread

How hantaviruses spread

The bank vole, a small rodent that can carry a hantavirus

The western deer mouse, another rodent that carries hantaviruses

Hantaviruses that make people sick mostly spread from rodents. In rodents, these viruses usually do not cause any symptoms. Infected rodents can spread the virus to other animals. This happens through tiny particles from their droppings, urine, saliva, or blood. It can also spread if animals eat contaminated food. The virus can live outside a host for several days. This helps it spread more easily.

Risk Factors for Infection

Certain things increase the risk of getting infected. Living in rural areas or places with poor hygiene can be risky. People who spend a lot of time outdoors are also at higher risk. This includes hikers, farmers, and forestry workers. Conditions that help rodents reproduce and spread can increase the chance of disease. For example, lots of rain can lead to more food for rodents. This makes their populations grow.

Human-to-Human Spread

The Andes virus, a type of hantavirus, has been thought to spread from person to person. This might happen after very close contact with an infected person. However, research has shown that there isn't enough strong evidence to fully support this. It might be possible between very close family members. Other hantaviruses are not known to spread from person to person.

Other Animals and the Environment

Besides rodents, hantaviruses have been found in other small mammals. These include moles, shrews, and bats. Human activities can also play a role in how hantaviruses spread. Cutting down forests or having too much farmland can destroy rodent habitats. This can bring rodents closer to human homes. Sewers and drainage systems can also be places where rodents live. This is especially true in areas with poor waste management.

Hantaviruses and the Environment

El Niño's effect on local climates

Rodents that carry hantaviruses live in many different places. These include deserts, forests, swamps, and fields. Changes in climate and the environment can increase contact between rodents and humans. This means more chances for people to be exposed to hantaviruses.

For example, in 1993, there was an outbreak in the United States. This happened after a period of heavy rainfall caused by El Niño. The rain led to a lot of plant growth, which meant more food for rodents. Their population grew quickly, and the virus spread more easily.

Rainfall can affect hantavirus spread in different ways. Heavy rain can lead to outbreaks in the following months. But it can also flood rodent homes, which might reduce their numbers. In places with wet and dry seasons, infections are more common during the wet season.

Temperature also plays a role. Higher temperatures can make it harder for the virus to survive outside a host. But it can also make rodents seek shelter in human buildings. Colder temperatures can help the virus survive longer outside a host. Extreme temperatures, whether hot or cold, are linked to fewer disease cases.

How Hantaviruses Work

Hantaviruses are very small. They have a special genetic material called RNA. This RNA is divided into three parts. Each part helps the virus make different proteins. These proteins are like tiny tools the virus uses. The virus particles are usually round. They have a protective outer layer called a lipid envelope. This envelope has spike-like proteins on its surface. These spikes help the virus attach to and enter cells.

The Virus Life Cycle

When a hantavirus enters your body, it looks for certain cells to infect. It mainly targets cells that line blood vessels and immune cells. The virus uses its spikes to attach to the surface of a cell. Then, it enters the cell. Once inside, the virus releases its genetic material. It uses the cell's own machinery to make many copies of itself. It also makes more viral proteins. These new parts then come together to form new virus particles. These new viruses then leave the cell to infect other cells. This process allows the virus to spread and cause illness.

How Hantaviruses Change Over Time

Hantaviruses can change over time. This happens through small changes in their genetic material, called mutations. Hantaviruses usually stay with one type of rodent. They evolve along with their hosts. But sometimes, they can jump to a new host species. Because hantaviruses have segmented genetic material, they can also swap parts with other hantaviruses. This is called reassortment. This swapping can create new types of viruses. It helps them adapt to different hosts and environments.

Types of Orthohantaviruses

Orthohantaviruses belong to the family Hantaviridae. There are 37 known species in this group. Each species is usually named after the place where it was first found.

Many other hantaviruses are still being studied and are not yet officially classified:

A Brief History of Hantaviruses

The first descriptions of illnesses like HFRS might go back to ancient China. During the Korean War (1950-1953), about 3,200 soldiers got sick near the Hantan river. This illness was called "Korean hemorrhagic fever." In 1978, scientists in South Korea found the virus responsible. They named it Hantaan virus after the river.

Later, other hantaviruses were found across Europe and Asia. In 1982, the World Health Organization (WHO) officially named the disease "hemorrhagic fever with renal syndrome." The group of viruses was named "hantaviruses" in 1985.

Vaccine Development

The first hantavirus vaccine, called Hantavax, was created in 1990. It helps protect against hantavirus strains found in Northeast Asia. However, this vaccine is not approved for use in Europe or the United States.

Discovery of Hantavirus Pulmonary Syndrome (HPS)

In 1993, a serious outbreak of breathing problems happened in the Four Corners region of the United States. Scientists discovered a new hantavirus was causing it. They named this virus Sin Nombre virus. This was the first time a hantavirus was found to cause severe lung disease. This new illness was named Hantavirus Pulmonary Syndrome (HPS). Since then, many other hantaviruses have been found in North and South America.

Recent Outbreaks

HFRS is still more common than HPS. More than 100,000 cases of HFRS happen each year. Only a few hundred cases of HPS are reported annually. In recent years, hantavirus outbreaks have been reported in places like Latin America, Europe, and North America.

A recent outbreak happened on the ship MV Hondius. It started on April 1, 2026, after the ship left Ushuaia, Argentina. The first death was reported on April 11. More cases and deaths followed in late April and early May. A second death occurred in Johannesburg on April 26. A third death happened onboard on May 2. On May 6, 2026, Swiss health officials confirmed that a passenger who had left the ship tested positive for Andes virus in Zurich. The World Health Organization continues to watch the situation closely.

See also

• Hantavirus pulmonary syndrome
• 1993 Four Corners hantavirus outbreak
• 2012 Yosemite hantavirus outbreak
• MV Hondius hantavirus outbreak
• MV Hondius hantavirus outbreak in the United States