Què és l’hantavirus? Símptomes i com es transmet aquesta infecció poc freqüent

What is hantavirus?

Hantavirus is a type of virus belonging to the Hantaviridae family, which includes more than 28 species named after the geographical regions where they were first identified. It is a zoonotic virus, meaning it is transmitted from animals to humans. The main reservoirs of hantavirus are wild rodents, particularly mice and rats, which can carry the virus without showing any symptoms.

There are different types of hantavirus worldwide, and not all of them cause the same disease. Depending on the region and the type of virus, infection may mainly result in:

• Hantavirus cardiopulmonary syndrome (HCPS), or New World hantavirus, more common in South America (Argentina, Chile, Paraguay, etc.).
• Haemorrhagic fever with renal syndrome (HFRS), or Old World hantavirus, more common in Eastern Europe and Asia (Russia, China, the Balkans region, Finland, etc.).

Although these diseases are uncommon, they can be severe and require specialised medical care.

How is hantavirus transmitted?

Transmission of hantavirus to humans mainly occurs through:

• Direct contact with urine, faeces or saliva of infected rodents
• Inhalation of aerosols from contaminated dried rodent droppings

These particles can remain suspended in the dust in the environment, for example when cleaning enclosed spaces, barns, sheds or poorly ventilated homes where rodents have been present.

In less frequent cases, transmission may also occur through:

• Direct contact with infected rodents
• Bites

Person-to-person transmission does not occur, with the exception of the Andes virus, although this route of transmission is very rare. When it does happen, it usually involves close and prolonged contact, typically among people living together.

What are the symptoms of hantavirus?

Hantavirus symptoms can vary depending on the type of infection and usually appear between 2 and 3 weeks after exposure to the virus, although the incubation period can extend up to 8 weeks. In the early stages, symptoms may be non-specific, making early identification difficult.

Initial phase (lasting 2 to 7 days):

• High fever
• Severe headache
• Muscle aches
• Extreme fatigue
• Nausea, vomiting or abdominal pain
• Eye pain and conjunctival injection

Advanced phase: a second phase may develop with more severe symptoms.

In the case of hantavirus pulmonary syndrome:

• Shortness of breath
• Cough
• Chest tightness and palpitations
• Build-up of fluid in the lungs

In haemorrhagic fever with renal syndrome:

• Impaired kidney function
• Reduced urine output
• Bleeding

If compatible symptoms appear, especially following contact with rodents or exposure to risk environments, it is essential to seek medical attention as early as possible.

Diagnosis and treatment

Hantavirus infection is confirmed through specific laboratory tests, such as blood tests. Currently, there is no specific antiviral treatment for this infection. Management is based on:

• Early medical care
• Supportive treatment
• Hospital admission in severe cases, sometimes in intensive care units

Early detection is key to improving disease outcomes. As there is no specific treatment, prevention is essential. Some recommendations include:

• Avoiding contact with rodents and their droppings.
• Ventilating enclosed spaces thoroughly before cleaning them.
• Avoiding dry sweeping or vacuuming areas with possible contamination; dampening surfaces beforehand with a disinfectant solution is preferable.
• Wearing gloves and a mask when cleaning areas where rodents may be present.
• Storing food in sealed containers and sealing possible entry points to homes.
• In endemic areas, keeping food out of reach of rodents and taking extra precautions during outdoor activities (camping, hiking, etc.).
• Staying informed, without alarmism.

Although recent cases of hantavirus have brought this infection back into the news, the risk to the general population remains low.